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Attempt to invoke virtual method 'void android.app.ActionBar.setDisplayHomeAsUpEnabled(boolean)' on a null object reference NullPointer [duplicate]

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What is a NullPointerException, and how do I fix it?
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Closed 7 years ago.
Having a few run-time issues with a navigation drawer i'm trying to test out...
The error I get is:
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.suzan.parentmeetme/com.example.suzan.parentmeetme.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.ActionBar.setDisplayHomeAsUpEnabled(boolean)' on a null object reference at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.ActionBar.setDisplayHomeAsUpEnabled(boolean)' on a null object reference
at com.example.suzan.parentmeetme.NavigationDrawerFragment.setUp(NavigationDrawerFragment.java:138)
at com.example.suzan.parentmeetme.MainActivity.onCreate(MainActivity.java:35)
at android.app.Activity.performCreate(Activity.java:6237)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476) 
at android.app.ActivityThread.-wrap11(ActivityThread.java) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:148) 
at android.app.ActivityThread.main(ActivityThread.java:5417) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 
12-30 21:45:47.250 27145-27145/? I/Process: Sending signal. PID: 27145 SIG: 9
I have a couple of java files:
MainActivity.java
package com.example.suzan.parentmeetme;
import android.app.ActionBar;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentManager;
import android.os.Bundle;
import android.support.v4.widget.DrawerLayout;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
public class MainActivity extends Activity
implements NavigationDrawerFragment.NavigationDrawerCallbacks {
// This navigation drawer frag will be responsible for the actions and behaviour of
// the navigation drawer
private NavigationDrawerFragment mNavigationDrawerFragment;
// Keeps track of the last screen we were on by storing the title name
private CharSequence mTitle;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mNavigationDrawerFragment = (NavigationDrawerFragment)getFragmentManager()
.findFragmentById(R.id.navigation_drawer);
mTitle = getTitle();
// Initialise the navigation drawer
mNavigationDrawerFragment.setUp(R.id.navigation_drawer, (DrawerLayout) findViewById(R.id.drawer_layout));
}
#Override
public void onNavigationDrawerItemSelected(int position)
{
Fragment fragment = null;
switch (position)
{
case 0:
fragment = new SettingsFragment();
break;
}
// update the main content by replacing fragments
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.container, fragment).commit();
}
public void onSectionAttached(int number)
{
switch (number)
{
case 1:
mTitle = getString(R.string.title_section1);
break;
}
}
public void restoreActionBar()
{
ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
actionBar.setDisplayShowTitleEnabled(true);
actionBar.setTitle(mTitle);
}
#Override
public boolean onCreateOptionsMenu(Menu menu)
{
if (!mNavigationDrawerFragment.isDrawerOpen())
{
// only display actions relevant to this screen
getMenuInflater().inflate(R.menu.sample, menu);
restoreActionBar();
return true;
}
return super.onCreateOptionsMenu(menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item)
{
// Handle action bar item clicks here.
// Action bar will handle clicks on home/up
// button, so long as parent activity is specified
// in AndroidManifest.xml
int id = item.getItemId();
if (id == R.id.action_settings)
{
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment
{
/**
* The fragment argument representing the section number for this
* fragment.
*/
private static final String ARG_SECTION_NUMBER = "section_number";
/**
* Returns a new instance of this fragment for the given section
* number.
*/
public static PlaceholderFragment newInstance(int sectionNumber) {
PlaceholderFragment fragment = new PlaceholderFragment();
Bundle args = new Bundle();
args.putInt(ARG_SECTION_NUMBER, sectionNumber);
fragment.setArguments(args);
return fragment;
}
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_layout, container, false);
return rootView;
}
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
((MainActivity) activity).onSectionAttached(
getArguments().getInt(ARG_SECTION_NUMBER));
}
}
}
NavigationDrawerFragment.java
package com.example.suzan.parentmeetme;
/**
* Created by Suzan on 30/12/2015.
*/
import android.app.Activity;
import android.app.ActionBar;
import android.app.Fragment;
import android.support.v4.app.ActionBarDrawerToggle;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.content.SharedPreferences;
import android.content.res.Configuration;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
/**
* Fragment used for managing interactions for and presentation of a navigation drawer.
* See the <a href="https://developer.android.com/design/patterns/navigation-drawer.html#Interaction">
* design guidelines</a> for a complete explanation of the behaviors implemented here.
*/
public class NavigationDrawerFragment extends Fragment {
/**
* Remember the position of the selected item.
*/
private static final String STATE_SELECTED_POSITION = "selected_navigation_drawer_position";
/**
* Per the design guidelines, you should show the drawer on launch until the user manually
* expands it. This shared preference tracks this.
*/
private static final String PREF_USER_LEARNED_DRAWER = "navigation_drawer_learned";
/**
* A pointer to the current callbacks instance (the Activity).
*/
private NavigationDrawerCallbacks mCallbacks;
/**
* Helper component that ties the action bar to the navigation drawer.
*/
private ActionBarDrawerToggle mDrawerToggle;
private DrawerLayout mDrawerLayout;
private ListView mDrawerListView;
private View mFragmentContainerView;
private int mCurrentSelectedPosition = 0;
private boolean mFromSavedInstanceState;
private boolean mUserLearnedDrawer;
public NavigationDrawerFragment() {
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Read in the flag indicating whether or not the user has demonstrated awareness of the
// drawer. See PREF_USER_LEARNED_DRAWER for details.
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(getActivity());
mUserLearnedDrawer = sp.getBoolean(PREF_USER_LEARNED_DRAWER, false);
if (savedInstanceState != null) {
mCurrentSelectedPosition = savedInstanceState.getInt(STATE_SELECTED_POSITION);
mFromSavedInstanceState = true;
}
// Select either the default item (0) or the last selected item.
selectItem(mCurrentSelectedPosition);
}
#Override
public void onActivityCreated (Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
// Indicate that this fragment would like to influence the set of actions in the action bar.
setHasOptionsMenu(true);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View myParentView = inflater.inflate(
R.layout.fragment_navigation_drawer, container, false);
mDrawerListView = (ListView) myParentView.findViewById(R.id.listview);
// the listview is the id you gave to you listview in xml
mDrawerListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
selectItem(position);
}
});
mDrawerListView.setAdapter(new ArrayAdapter<String>(
getActivity(),
android.R.layout.simple_list_item_activated_1,
android.R.id.text1,
new String[]{
getString(R.string.title_section1),
getString(R.string.title_section2),
getString(R.string.title_section3),
}));
mDrawerListView.setItemChecked(mCurrentSelectedPosition, true);
return mDrawerListView;
}
public boolean isDrawerOpen() {
return mDrawerLayout != null && mDrawerLayout.isDrawerOpen(mFragmentContainerView);
}
/**
* Users of this fragment must call this method to set up the navigation drawer interactions.
*
* #param fragmentId The android:id of this fragment in its activity's layout.
* #param drawerLayout The DrawerLayout containing this fragment's UI.
*/
public void setUp(int fragmentId, DrawerLayout drawerLayout) {
mFragmentContainerView = getActivity().findViewById(fragmentId);
mDrawerLayout = drawerLayout;
// set a custom shadow that overlays the main content when the drawer opens
mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START);
// set up the drawer's list view with items and click listener
ActionBar actionBar = getActionBar();
actionBar.setDisplayHomeAsUpEnabled(true);
actionBar.setHomeButtonEnabled(true);
// ActionBarDrawerToggle ties together the the proper interactions
// between the navigation drawer and the action bar app icon.
mDrawerToggle = new ActionBarDrawerToggle(
getActivity(), /* host Activity */
mDrawerLayout, /* DrawerLayout object */
R.drawable.ic_drawer, /* nav drawer image to replace 'Up' caret */
R.string.navigation_drawer_open, /* "open drawer" description for accessibility */
R.string.navigation_drawer_close /* "close drawer" description for accessibility */
) {
#Override
public void onDrawerClosed(View drawerView) {
super.onDrawerClosed(drawerView);
if (!isAdded()) {
return;
}
getActivity().invalidateOptionsMenu(); // calls onPrepareOptionsMenu()
}
#Override
public void onDrawerOpened(View drawerView) {
super.onDrawerOpened(drawerView);
if (!isAdded()) {
return;
}
if (!mUserLearnedDrawer) {
// The user manually opened the drawer; store this flag to prevent auto-showing
// the navigation drawer automatically in the future.
mUserLearnedDrawer = true;
SharedPreferences sp = PreferenceManager
.getDefaultSharedPreferences(getActivity());
sp.edit().putBoolean(PREF_USER_LEARNED_DRAWER, true).apply();
}
getActivity().invalidateOptionsMenu(); // calls onPrepareOptionsMenu()
}
};
// If the user hasn't 'learned' about the drawer, open it to introduce them to the drawer,
// per the navigation drawer design guidelines.
if (!mUserLearnedDrawer && !mFromSavedInstanceState) {
mDrawerLayout.openDrawer(mFragmentContainerView);
}
// Defer code dependent on restoration of previous instance state.
mDrawerLayout.post(new Runnable() {
#Override
public void run() {
mDrawerToggle.syncState();
}
});
mDrawerLayout.setDrawerListener(mDrawerToggle);
}
private void selectItem(int position) {
mCurrentSelectedPosition = position;
if (mDrawerListView != null) {
mDrawerListView.setItemChecked(position, true);
}
if (mDrawerLayout != null) {
mDrawerLayout.closeDrawer(mFragmentContainerView);
}
if (mCallbacks != null) {
mCallbacks.onNavigationDrawerItemSelected(position);
}
}
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mCallbacks = (NavigationDrawerCallbacks) activity;
} catch (ClassCastException e) {
throw new ClassCastException("Activity must implement NavigationDrawerCallbacks.");
}
}
#Override
public void onDetach() {
super.onDetach();
mCallbacks = null;
}
#Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt(STATE_SELECTED_POSITION, mCurrentSelectedPosition);
}
#Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
// Forward the new configuration the drawer toggle component.
mDrawerToggle.onConfigurationChanged(newConfig);
}
#Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
// If the drawer is open, show the global app actions in the action bar. See also
// showGlobalContextActionBar, which controls the top-left area of the action bar.
if (mDrawerLayout != null && isDrawerOpen()) {
inflater.inflate(R.menu.global, menu);
showGlobalContextActionBar();
}
super.onCreateOptionsMenu(menu, inflater);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if (mDrawerToggle.onOptionsItemSelected(item)) {
return true;
}
if (item.getItemId() == R.id.action_example) {
Toast.makeText(getActivity(), "Example action.", Toast.LENGTH_SHORT).show();
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* Per the navigation drawer design guidelines, updates the action bar to show the global app
* 'context', rather than just what's in the current screen.
*/
private void showGlobalContextActionBar() {
ActionBar actionBar = getActionBar();
actionBar.setDisplayShowTitleEnabled(true);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
actionBar.setTitle(R.string.app_name);
}
private ActionBar getActionBar() {
return getActivity().getActionBar();
}
/**
* Callbacks interface that all activities using this fragment must implement.
*/
public static interface NavigationDrawerCallbacks {
/**
* Called when an item in the navigation drawer is selected.
*/
void onNavigationDrawerItemSelected(int position);
}
}
And I've got a few XML files:
activity_main.xml
<!-- A DrawerLayout is intended to be used as the top-level content view using match_parent for both width and height to consume the full space available. -->
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<!-- As the main content view, the view below consumes the entire
space available using match_parent in both dimensions. -->
<FrameLayout
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<!-- android:layout_gravity="start" tells DrawerLayout to treat
this as a sliding drawer on the left side for left-to-right
languages and on the right side for right-to-left languages.
If you're not building against API 17 or higher, use
android:layout_gravity="left" instead. -->
<!-- The drawer is given a fixed width in dp and extends the full height of
the container. -->
<fragment android:id="#+id/navigation_drawer"
android:layout_width="#dimen/navigation_drawer_width"
android:layout_height="match_parent"
android:layout_gravity="start"
android:name="com.example.suzan.parentmeetme.NavigationDrawerFragment"
tools:layout="#layout/fragment_navigation_drawer" />
</android.support.v4.widget.DrawerLayout>
fragment_navigation_layout.xml
<ListView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:choiceMode="singleChoice"
android:divider="#android:color/transparent"
android:dividerHeight="0dp"
android:background="#cccc"
android:id="#+id/listview"
tools:context=".NavigationDrawerFragment" />
Could anyone figure out what I might be doing wrong? Been staring at this for hours and seriously can't work it out.....
Thanks!

Make sure you have referenced
public class MainActivity extends ActionBarActivity {
...
}
and change
ActionBar bar = getActionBar();
to
ActionBar bar =getActivity().getSupportActionBar();
Reference
http://developer.android.com/guide/topics/ui/actionbar.html

First change your class extension
public class MainActivity extends AppCompatActivity{
And then get your support action bar adding the following code to the 'onCreateView' method
assert getSupportActionBar() != null;
getSupportActionBar().setDisplayHomeAsUpEnabled(true);

Android nullpointer Screenslider (view pager)

I have downloaded the demo screen slider from android (https://developer.android.com/training/animation/screen-slide.html).
I've tried to put this in my own project but I get this error:
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.pws.test.demo/com.pws.test.demo.E_D_Uitgebreid}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2331)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2389)
at android.app.ActivityThread.access$900(ActivityThread.java:169)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1277)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5479)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.pws.test.demo.E_D_Uitgebreid.onCreate(E_D_Uitgebreid.java:51)
at android.app.Activity.performCreate(Activity.java:5451)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1093)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2295)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2389)
at android.app.ActivityThread.access$900(ActivityThread.java:169)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1277)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5479)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
at dalvik.system.NativeStart.main(Native Method)
This is my code:
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.support.v4.app.NavUtils;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.Menu;
import android.view.MenuItem;
/**
* Demonstrates a "screen-slide" animation using a {#link ViewPager}. Because {#link ViewPager}
* automatically plays such an animation when calling {#link ViewPager#setCurrentItem(int)}, there
* isn't any animation-specific code in this sample.
*
* <p>This sample shows a "next" button that advances the user to the next step in a wizard,
* animating the current screen out (to the left) and the next screen in (from the right). The
* reverse animation is played when the user presses the "previous" button.</p>
*
* #see
*/
public class E_D_Uitgebreid extends FragmentActivity {
/**
* The number of pages (wizard steps) to show in this demo.
*/
private static final int NUM_PAGES = 3;
/**
* The pager widget, which handles animation and allows swiping horizontally to access previous
* and next wizard steps.
*/
private ViewPager mPager;
/**
* The pager adapter, which provides the pages to the view pager widget.
*/
private PagerAdapter mPagerAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_e__d__uitgebreid__fragment);
// Instantiate a ViewPager and a PagerAdapter.
mPager = (ViewPager) findViewById(R.id.pager);
mPagerAdapter = new ScreenSlidePagerAdapter(getSupportFragmentManager());
mPager.setAdapter(mPagerAdapter);
mPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
#Override
public void onPageSelected(int position) {
// When changing pages, reset the action bar actions since they are dependent
// on which page is currently active. An alternative approach is to have each
// fragment expose actions itself (rather than the activity exposing actions),
// but for simplicity, the activity provides the actions in this sample.
invalidateOptionsMenu();
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
getMenuInflater().inflate(R.menu.menu_e__d__uitgebreid, menu);
menu.findItem(R.id.action_previous).setEnabled(mPager.getCurrentItem() > 0);
// Add either a "next" or "finish" button to the action bar, depending on which page
// is currently selected.
MenuItem item = menu.add(Menu.NONE, R.id.action_next, Menu.NONE,
(mPager.getCurrentItem() == mPagerAdapter.getCount() - 1)
? R.string.action_finish
: R.string.action_next);
item.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM | MenuItem.SHOW_AS_ACTION_WITH_TEXT);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
// Navigate "up" the demo structure to the launchpad activity.
// See http://developer.android.com/design/patterns/navigation.html for more.
NavUtils.navigateUpTo(this, new Intent(this, D_D_RondleidingMenu.class));
return true;
case R.id.action_previous:
// Go to the previous step in the wizard. If there is no previous step,
// setCurrentItem will do nothing.
mPager.setCurrentItem(mPager.getCurrentItem() - 1);
return true;
case R.id.action_next:
// Advance to the next step in the wizard. If there is no next step, setCurrentItem
// will do nothing.
mPager.setCurrentItem(mPager.getCurrentItem() + 1);
return true;
}
return super.onOptionsItemSelected(item);
}
private class ScreenSlidePagerAdapter extends FragmentStatePagerAdapter {
public ScreenSlidePagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
return E_D_Uitgebreid_Fragment.create(position);
}
#Override
public int getCount() {
return NUM_PAGES;
}
}
}
And the fragment:
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
/**
* A fragment representing a single step in a wizard. The fragment shows a dummy title indicating
* the page number, along with some dummy text.
*
* <p>This class is used by the and {#link
* } samples.</p>
*/
public class E_D_Uitgebreid_Fragment extends Fragment {
/**
* The argument key for the page number this fragment represents.
*/
public static final String ARG_PAGE = "page";
/**
* The fragment's page number, which is set to the argument value for {#link #ARG_PAGE}.
*/
private int mPageNumber;
/**
* Factory method for this fragment class. Constructs a new fragment for the given page number.
*/
public static E_D_Uitgebreid_Fragment create(int pageNumber) {
E_D_Uitgebreid_Fragment fragment = new E_D_Uitgebreid_Fragment();
Bundle args = new Bundle();
args.putInt(ARG_PAGE, pageNumber);
fragment.setArguments(args);
return fragment;
}
public E_D_Uitgebreid_Fragment() {
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mPageNumber = getArguments().getInt(ARG_PAGE);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout containing a title and body text.
ViewGroup rootView = (ViewGroup) inflater
.inflate(R.layout.activity_e__d__uitgebreid__fragment, container, false);
// Set the title view to show the page number.
((TextView) rootView.findViewById(android.R.id.text1)).setText(
Articles.paginatitel[mPageNumber]);
((TextView) rootView.findViewById(android.R.id.text2)).setText(
Articles.paginainhoud[mPageNumber]);
((ImageView) rootView.findViewById(android.R.id.background)).setImageResource(Articles.afbeelding[mPageNumber]);
return rootView;
}
/**
* Returns the page number represented by this fragment object.
*/
public int getPageNumber() {
return mPageNumber;
}
}
And also the menu activity:
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
public class D_D_RondleidingMenu extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_d__d__rondleiding_menu);
SetupUitgebreideRondleidingButton();
}
private void SetupUitgebreideRondleidingButton() {
Button MessageButton = (Button) findViewById(R.id.settingsbutton);
MessageButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
startActivity(new Intent(D_D_RondleidingMenu.this, E_D_Uitgebreid.class));
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_d__d__rondleiding_menu, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
activity_e_d_uitgebreid_fragment.xml:
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/content"
android:layout_width="match_parent"
android:layout_height="match_parent">
<!-- Dummy content. -->
<LinearLayout android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="16dp">
<ImageView android:id="#android:id/background"
android:layout_width="wrap_content"
android:layout_height="150dp"
android:layout_gravity="center_horizontal"
/>
<TextView android:id="#android:id/text1"
style="?android:textAppearanceLarge"
android:textStyle="bold"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="16dp" />
<TextView android:id="#android:id/text2"
style="?android:textAppearanceMedium"
android:lineSpacingMultiplier="1.2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="#string/lorem_ipsum"
/>
</LinearLayout>
</ScrollView>
I've already changed this, but this didn't work:
private class ScreenSlidePagerAdapter extends FragmentStatePagerAdapter {
public ScreenSlidePagerAdapter(android.support.v4.app.FragmentManager fm) {
super(fm);
}
and this:
#Override
public android.support.v4.app.Fragment getItem(int position) {
return E_D_Uitgebreid_Fragment.create(position);
}

ensure that the button with ID R.id.settingsbutton is exist in layout R.layout.activity_d__d__rondleiding_menu if exist please set activity_d__d__rondleiding_menu XML

Problems while switching activity using intent

I am trying to create a student management application. So far I have made a login page. I am a beginner to android so I have downloaded another sample activity to understand how to link to activites using intent. So far as soon as I click on login, the app crashes. Could anyone help me understand what is going wrong?
This is my Login Page (MainActivity.java).
package zade.example.com.zade;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends Activity {
private EditText username = null;
private EditText password = null;
private Button login;
int counter = 3;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
username = (EditText) findViewById(R.id.eno);
password = (EditText) findViewById(R.id.password);
login = (Button) findViewById(R.id.login_button);
}
public void login(View view) {
if (username.getText().toString().equals("1") &&
password.getText().toString().equals("a")) {
Toast.makeText(getApplicationContext(), "Login Successful",
Toast.LENGTH_SHORT).show();
Intent intent = new Intent(this, Home.class);
this.startActivity ( intent );
}
else {
Toast.makeText(getApplicationContext(), "Wrong Credentials",
Toast.LENGTH_SHORT).show();
counter--;
if (counter == 0) {
login.setEnabled(false);
}
}
}
}
This is the Home.java (Home activity)
package zade.example.com.zade;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.SearchManager;
import android.content.Intent;
import android.content.res.Configuration;
import android.os.Bundle;
import android.support.v4.app.ActionBarDrawerToggle;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.Toast;
import java.util.Locale;
public class Home extends Activity {
private DrawerLayout mDrawerLayout;
private ListView mDrawerList;
private ActionBarDrawerToggle mDrawerToggle;
private CharSequence mDrawerTitle;
private CharSequence mTitle;
private String[] mPlanetTitles;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
Intent intent = getIntent();
mTitle = mDrawerTitle = getTitle();
mPlanetTitles = getResources().getStringArray(R.array.planets_array);
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
mDrawerList = (ListView) findViewById(R.id.left_drawer);
// set a custom shadow that overlays the main content when the drawer opens
mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START);
// set up the drawer's list view with items and click listener
mDrawerList.setAdapter(new ArrayAdapter<String>(this,
R.layout.drawer_list_item, mPlanetTitles));
mDrawerList.setOnItemClickListener(new DrawerItemClickListener());
// enable ActionBar app icon to behave as action to toggle nav drawer
getActionBar().setDisplayHomeAsUpEnabled(true);
getActionBar().setHomeButtonEnabled(true);
// ActionBarDrawerToggle ties together the the proper interactions
// between the sliding drawer and the action bar app icon
mDrawerToggle = new ActionBarDrawerToggle(
this, /* host Activity */
mDrawerLayout, /* DrawerLayout object */
R.drawable.ic_drawer, /* nav drawer image to replace 'Up' caret */
R.string.drawer_open, /* "open drawer" description for accessibility */
R.string.drawer_close /* "close drawer" description for accessibility */
) {
public void onDrawerClosed(View view) {
getActionBar().setTitle(mTitle);
invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
}
public void onDrawerOpened(View drawerView) {
getActionBar().setTitle(mDrawerTitle);
invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
}
};
mDrawerLayout.setDrawerListener(mDrawerToggle);
if (savedInstanceState == null) {
selectItem(0);
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu_home, menu);
return super.onCreateOptionsMenu(menu);
}
/* Called whenever we call invalidateOptionsMenu() */
#Override
public boolean onPrepareOptionsMenu(Menu menu) {
// If the nav drawer is open, hide action items related to the content view
boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
menu.findItem(R.id.action_websearch).setVisible(!drawerOpen);
return super.onPrepareOptionsMenu(menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// The action bar home/up action should open or close the drawer.
// ActionBarDrawerToggle will take care of this.
if (mDrawerToggle.onOptionsItemSelected(item)) {
return true;
}
// Handle action buttons
switch(item.getItemId()) {
case R.id.action_websearch:
// create intent to perform web search for this planet
Intent intent = new Intent(Intent.ACTION_WEB_SEARCH);
intent.putExtra(SearchManager.QUERY, getActionBar().getTitle());
// catch event that there's no activity to handle intent
if (intent.resolveActivity(getPackageManager()) != null) {
startActivity(intent);
} else {
Toast.makeText(this, R.string.app_not_available, Toast.LENGTH_LONG).show();
}
return true;
default:
return super.onOptionsItemSelected(item);
}
}
/* The click listner for ListView in the navigation drawer */
private class DrawerItemClickListener implements ListView.OnItemClickListener {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
selectItem(position);
}
}
private void selectItem(int position) {
// update the main content by replacing fragments
Fragment fragment = new PlanetFragment();
Bundle args = new Bundle();
args.putInt(PlanetFragment.ARG_PLANET_NUMBER, position);
fragment.setArguments(args);
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit();
// update selected item and title, then close the drawer
mDrawerList.setItemChecked(position, true);
setTitle(mPlanetTitles[position]);
mDrawerLayout.closeDrawer(mDrawerList);
}
#Override
public void setTitle(CharSequence title) {
mTitle = title;
getActionBar().setTitle(mTitle);
}
/**
* When using the ActionBarDrawerToggle, you must call it during
* onPostCreate() and onConfigurationChanged()...
*/
#Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
// Sync the toggle state after onRestoreInstanceState has occurred.
mDrawerToggle.syncState();
}
#Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
// Pass any configuration change to the drawer toggls
mDrawerToggle.onConfigurationChanged(newConfig);
}
/**
* Fragment that appears in the "content_frame", shows a planet
*/
public static class PlanetFragment extends Fragment {
public static final String ARG_PLANET_NUMBER = "planet_number";
public PlanetFragment() {
// Empty constructor required for fragment subclasses
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_planet, container, false);
int i = getArguments().getInt(ARG_PLANET_NUMBER);
String planet = getResources().getStringArray(R.array.planets_array)[i];
int imageId = getResources().getIdentifier(planet.toLowerCase(Locale.getDefault()),
"drawable", getActivity().getPackageName());
((ImageView) rootView.findViewById(R.id.image)).setImageResource(imageId);
getActivity().setTitle(planet);
return rootView;
}
}
}
Logcat
--------- beginning of crash
01-19 14:35:25.458 2116-2116/zade.example.com.zade E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: zade.example.com.zade, PID: 2116
java.lang.RuntimeException: Unable to start activity ComponentInfo{zade.example.com.zade/zade.example.com.zade.Home}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.ActionBar.setDisplayHomeAsUpEnabled(boolean)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
at android.app.ActivityThread.access$800(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.ActionBar.setDisplayHomeAsUpEnabled(boolean)' on a null object reference
at zade.example.com.zade.Home.onCreate(Home.java:55)
at android.app.Activity.performCreate(Activity.java:5933)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
            at android.app.ActivityThread.access$800(ActivityThread.java:144)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="zade.example.com.zade" >
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name=".MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".Home"
android:label="#string/title_activity_home"
android:parentActivityName=".MainActivity" >
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="zade.example.com.zade.MainActivity" />
</activity>
</application>
</manifest>

Instead of using
getActionBar().setDisplayHomeAsUpEnabled(true);
getActionBar().setHomeButtonEnabled(true);
use
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setHomeButtonEnabled(true);
Also make sure that you use getSupportActionBar() in place of getActionBar() in all occurrences.

This is because you are getting null when you are using getActionBar() as in LogCat it say
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.ActionBar.setDisplayHomeAsUpEnabled(boolean)' on a null object reference
Use getSupportActionBar(), hope it helps.
If you are still getting the crash after doing this please tell me.

Check whether you added the second activity class in your AndroidManifest.XML file as a child of tag.
the following code might help:
login = (Button) findViewById(R.id.login_button);
login.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
//change the page and other stuffs you wish to when
//user will hit logIn button
}
});

It should not be so hard
1)Create 2 java files Activity1.java and activity2.java create suitables xml files if you want.
2)declare the second activity in the manifest.xml file within the
<Application> </Application tags.
in this activities onCreate write the following code
Intent intent = new Intent(this,Activity2.class);
startActivity(intent);

How can I add a large profile picture to my navigation drawer?

So, a couple of days ago I started working on my very first app. It's an app with a navigation drawer where users can set some website shortcuts to be displayed in the navigation drawer. If a user clicks on a website it opens in a webview. Really nothing fancy, but it's a concept I came up with to train my Android knowledge.
I finished the basics of this app this morning with some help, but now I want to add a large profile picture to the navigation drawer. (You can see it here on the left: http://www.droid-life.com/wp-content/uploads/2013/12/new-foursquare.jpg)
I understand that I should add an <ImageView> to the navigation drawer, but every time I try that the log keeps saying I have junk in my XML...
Below you can find the code I already wrote. I hope you guys can help me...
Main.java
package test.webviewapp;
import android.app.Activity;
import android.app.ProgressDialog;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.webkit.WebViewClient;
public class Main
extends ActionBarActivity
implements NavigationDrawerFragment.NavigationDrawerCallbacks
{
/**
* Fragment managing the behaviors, interactions and presentation of the
* navigation drawer.
*/
private NavigationDrawerFragment mNavigationDrawerFragment;
/**
* Used to store the last screen title. For use in
* {#link #restoreActionBar()}.
*/
private CharSequence mTitle;
// we need a class level references to some objects to be able to modify the
// target address outside of onCreate()
private WebView myWebView;
private ActionBar actionBar;
private ProgressDialog progressDialog;
// keep the pair of String arrays of site names and addresses
private String[] siteNames;
private String[] siteAddresses;
private static final String TAG = "MainActivity";
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// grab the needed website arrays
siteNames = getResources().getStringArray(R.array.site_names);
siteAddresses = getResources().getStringArray(R.array.site_addresses);
// set up WebView. initial page load comes from NavDrawerFragment attach
myWebView = (WebView) findViewById(R.id.main_webview);
myWebView.getSettings().setJavaScriptEnabled(true);
myWebView.setWebChromeClient(new WebChromeClient());
myWebView.setWebViewClient(new WebViewClient()
{
#Override
public void onPageFinished(WebView view, String url)
{
// when a page has finished loading dismiss any progress dialog
if (progressDialog != null && progressDialog.isShowing())
{
progressDialog.dismiss();
}
String javascript="javascript:"+
"document.getElementById('menu-toggle').css('display','none');";
myWebView.evaluateJavascript(javascript, null);
}
});
// Set up the drawer.
mNavigationDrawerFragment = (NavigationDrawerFragment) getSupportFragmentManager()
.findFragmentById(R.id.navigation_drawer);
mNavigationDrawerFragment.setUp(R.id.navigation_drawer,
(DrawerLayout) findViewById(R.id.drawer_layout));
}
#Override
public void onNavigationDrawerItemSelected(int siteIndex)
{
// user selected page load
Log.d(TAG, "(onNavSelect) received index: " + siteIndex);
loadWebPage(siteIndex);
}
public void onSectionAttached(int siteIndex)
{
// initial page load. not user selected.
loadWebPage(siteIndex);
}
public void restoreActionBar()
{
actionBar = getSupportActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
actionBar.setDisplayShowTitleEnabled(true);
actionBar.setTitle(mTitle);
}
private void loadWebPage(int siteIndex)
{
// lets show a progress indicator instead of a blank screen
if (progressDialog == null)
{
initProgressDialog();
}
progressDialog.show();
// load the page
Log.d(TAG, "(loadWebPage) Loading page: " + siteNames[siteIndex] + "("
+ siteAddresses[siteIndex] + ")");
mTitle = siteNames[siteIndex];
if (actionBar == null)
{
restoreActionBar();
}
else
{
actionBar.setTitle(mTitle);
}
myWebView.getSettings().setJavaScriptEnabled(true);
myWebView.loadUrl(siteAddresses[siteIndex]);
myWebView.loadUrl(siteAddresses[siteIndex]);
// progressDialog gets dismissed above in WebViewclient declaration
}
private void initProgressDialog()
{
progressDialog = new ProgressDialog(this, ProgressDialog.STYLE_SPINNER);
progressDialog.setIndeterminate(true);
progressDialog.setMessage(getString(R.string.page_load_progress_message));
}
#Override
public boolean onCreateOptionsMenu(Menu menu)
{
if (!mNavigationDrawerFragment.isDrawerOpen())
{
// Only show items in the action bar relevant to this screen
// if the drawer is not showing. Otherwise, let the drawer
// decide what to show in the action bar.
getMenuInflater().inflate(R.menu.global, menu);
restoreActionBar();
return true;
}
return super.onCreateOptionsMenu(menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item)
{
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
if (actionBar == null)
{
restoreActionBar();
}
else
{
}
int id = item.getItemId();
if (id == R.id.action_settings)
{
myWebView.loadUrl(settingsview);
myWebView.loadUrl(settingsview);
actionBar.setTitle("Settings");
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment
extends Fragment
{
/**
* The fragment argument representing the section number for this
* fragment.
*/
private static final String ARG_SELECTED_SITE_INDEX = "selected_site_index";
/**
* Returns a new instance of this fragment for the given section
* number.
*/
public static PlaceholderFragment newInstance(int siteIndex)
{
PlaceholderFragment fragment = new PlaceholderFragment();
Bundle args = new Bundle();
args.putInt(ARG_SELECTED_SITE_INDEX, siteIndex);
fragment.setArguments(args);
return fragment;
}
public PlaceholderFragment()
{}
#Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container,
Bundle savedInstanceState)
{
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
}
#Override
public void onAttach(Activity activity)
{
super.onAttach(activity);
// Here is where you can define the default page you want loaded
// or if you want to save/restore the last page viewed etc.
((Main) activity)
.onSectionAttached(getArguments().getInt(ARG_SELECTED_SITE_INDEX));
}
}
}
NavigationDrawerFragment.java
package test.webviewapp;
import android.app.Activity;
import android.content.SharedPreferences;
import android.content.res.Configuration;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.support.v4.app.ActionBarDrawerToggle;
import android.support.v4.app.Fragment;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
/**
* Fragment used for managing interactions for and presentation of a
* navigation drawer. See the <a href=
* "https://developer.android.com/design/patterns/navigation-drawer.html#Interaction"
* > design guidelines</a> for a complete explanation of the behaviors
* implemented here.
*/
public class NavigationDrawerFragment
extends Fragment
implements AdapterView.OnItemClickListener
{
private String[] siteNames;
private static final String TAG = "NavDrawerFrag";
/**
* Remember the position of the selected item.
*/
private static final String STATE_SELECTED_POSITION = "selected_navigation_drawer_position";
/**
* Per the design guidelines, you should show the drawer on launch until
* the user manually expands it. This shared preference tracks this.
*/
private static final String PREF_USER_LEARNED_DRAWER = "navigation_drawer_learned";
/**
* A pointer to the current callbacks instance (the Activity).
*/
private NavigationDrawerCallbacks mCallbacks;
/**
* Helper component that ties the action bar to the navigation drawer.
*/
private ActionBarDrawerToggle mDrawerToggle;
private DrawerLayout mDrawerLayout;
private ListView mDrawerListView;
private View mFragmentContainerView;
private int mCurrentSelectedPosition = 0;
private boolean mFromSavedInstanceState;
private boolean mUserLearnedDrawer;
public NavigationDrawerFragment()
{}
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
// Read in the flag indicating whether or not the user has demonstrated awareness of the
// drawer. See PREF_USER_LEARNED_DRAWER for details.
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(getActivity());
mUserLearnedDrawer = sp.getBoolean(PREF_USER_LEARNED_DRAWER, false);
if (savedInstanceState != null)
{
mCurrentSelectedPosition = savedInstanceState.getInt(STATE_SELECTED_POSITION);
mFromSavedInstanceState = true;
}
// Select either the default item (0) or the last selected item.
// too early to select an item
//selectItem(mCurrentSelectedPosition);
}
#Override
public void onActivityCreated(Bundle savedInstanceState)
{
super.onActivityCreated(savedInstanceState);
// Indicate that this fragment would like to influence the set of actions in the action bar.
setHasOptionsMenu(true);
selectItem(mCurrentSelectedPosition);
}
#Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container,
Bundle savedInstanceState)
{
siteNames = getActivity().getResources().getStringArray(R.array.site_names);
Log.d(TAG, "number of sites loaded: " + siteNames.length);
mDrawerListView = (ListView) inflater.inflate(R.layout.fragment_navigation_drawer,
container,
false);
// neater to implement OnItemClickListener and define onClick() later
mDrawerListView.setOnItemClickListener(this);
String[] siteNames = getActivity().getResources().getStringArray(R.array.site_names);
mDrawerListView.setAdapter(new ArrayAdapter<String>(getActionBar().getThemedContext(),
android.R.layout.simple_list_item_1, android.R.id.text1, siteNames));
mDrawerListView.setItemChecked(mCurrentSelectedPosition, true);
return mDrawerListView;
}
public boolean isDrawerOpen()
{
return mDrawerLayout != null && mDrawerLayout.isDrawerOpen(mFragmentContainerView);
}
/**
* Users of this fragment must call this method to set up the navigation
* drawer interactions.
*
* #param fragmentId
* The android:id of this fragment in its activity's layout.
* #param drawerLayout
* The DrawerLayout containing this fragment's UI.
*/
public void setUp(int fragmentId, DrawerLayout drawerLayout)
{
mFragmentContainerView = getActivity().findViewById(fragmentId);
mDrawerLayout = drawerLayout;
// set a custom shadow that overlays the main content when the drawer opens
//mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START);
// set up the drawer's list view with items and click listener
ActionBar actionBar = getActionBar();
actionBar.setDisplayHomeAsUpEnabled(true);
actionBar.setHomeButtonEnabled(true);
// ActionBarDrawerToggle ties together the the proper interactions
// between the navigation drawer and the action bar app icon.
mDrawerToggle = new ActionBarDrawerToggle(getActivity(), mDrawerLayout,
R.drawable.ic_drawer, R.string.navigation_drawer_open,
R.string.navigation_drawer_close)
{
#Override
public void onDrawerClosed(View drawerView)
{
super.onDrawerClosed(drawerView);
if (!isAdded())
{
return;
}
getActivity().supportInvalidateOptionsMenu(); // calls onPrepareOptionsMenu()
}
#Override
public void onDrawerOpened(View drawerView)
{
super.onDrawerOpened(drawerView);
if (!isAdded())
{
return;
}
if (!mUserLearnedDrawer)
{
// The user manually opened the drawer; store this flag to prevent auto-showing
// the navigation drawer automatically in the future.
mUserLearnedDrawer = true;
SharedPreferences sp = PreferenceManager
.getDefaultSharedPreferences(getActivity());
sp.edit().putBoolean(PREF_USER_LEARNED_DRAWER, true).apply();
}
getActivity().supportInvalidateOptionsMenu(); // calls onPrepareOptionsMenu()
}
};
// If the user hasn't 'learned' about the drawer, open it to introduce them to the drawer,
// per the navigation drawer design guidelines.
if (!mUserLearnedDrawer && !mFromSavedInstanceState)
{
mDrawerLayout.openDrawer(mFragmentContainerView);
}
// Defer code dependent on restoration of previous instance state.
mDrawerLayout.post(new Runnable()
{
#Override
public void run()
{
mDrawerToggle.syncState();
}
});
mDrawerLayout.setDrawerListener(mDrawerToggle);
}
private void selectItem(int siteIndex)
{
mCurrentSelectedPosition = siteIndex;
if (mDrawerListView != null)
{
Log.d(TAG, "(select) list ok");
mDrawerListView.setItemChecked(siteIndex, true);
}
if (mDrawerLayout != null)
{
Log.d(TAG, "(select) drawer ok");
mDrawerLayout.closeDrawer(mFragmentContainerView);
}
if (mCallbacks != null)
{
Log.d(TAG, "(select) callback...");
mCallbacks.onNavigationDrawerItemSelected(siteIndex);
}
}
#Override
public void onAttach(Activity activity)
{
super.onAttach(activity);
try
{
mCallbacks = (NavigationDrawerCallbacks) activity;
}
catch (ClassCastException e)
{
throw new ClassCastException("Activity must implement NavigationDrawerCallbacks.");
}
}
#Override
public void onDetach()
{
super.onDetach();
mCallbacks = null;
}
#Override
public void onSaveInstanceState(Bundle outState)
{
super.onSaveInstanceState(outState);
outState.putInt(STATE_SELECTED_POSITION, mCurrentSelectedPosition);
}
#Override
public void onConfigurationChanged(Configuration newConfig)
{
super.onConfigurationChanged(newConfig);
// Forward the new configuration the drawer toggle component.
mDrawerToggle.onConfigurationChanged(newConfig);
}
#Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater)
{
// If the drawer is open, show the global app actions in the action bar. See also
// showGlobalContextActionBar, which controls the top-left area of the action bar.
if (mDrawerLayout != null && isDrawerOpen())
{
inflater.inflate(R.menu.global, menu);
showGlobalContextActionBar();
}
super.onCreateOptionsMenu(menu, inflater);
}
#Override
public boolean onOptionsItemSelected(MenuItem item)
{
if (mDrawerToggle.onOptionsItemSelected(item))
{
//fragment = new PlanetFragment();
}
return super.onOptionsItemSelected(item);
}
/**
* Per the navigation drawer design guidelines, updates the action bar to
* show the global app 'context', rather than just what's in the current
* screen.
*/
private void showGlobalContextActionBar()
{
ActionBar actionBar = getActionBar();
actionBar.setDisplayShowTitleEnabled(true);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
actionBar.setTitle(R.string.app_name);
}
private ActionBar getActionBar()
{
return ((ActionBarActivity) getActivity()).getSupportActionBar();
}
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id)
{
Log.i(TAG, "(Click) index: " + position);
Log.i(TAG, "(Click) site: " + siteNames[position]);
selectItem(position);
}
/**
* Callbacks interface that all activities using this fragment must
* implement.
*/
public static interface NavigationDrawerCallbacks
{
/**
* Called when an item in the navigation drawer is selected.
*/
void onNavigationDrawerItemSelected(int position);
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<WebView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/main_webview"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
<fragment
android:id="#+id/navigation_drawer"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="start"
android:name="test.webdrawerapp.NavigationDrawerFragment"
tools:layout="#layout/fragment_navigation_drawer"/>
</android.support.v4.widget.DrawerLayout>
fragment_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".main$PlaceholderFragment">
</RelativeLayout>
fragment_navigation_drawer.xml
<ListView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:choiceMode="singleChoice"
android:divider="#android:color/transparent"
android:dividerHeight="0dp"
android:background="#000"
tools:context=".NavigationDrawerFragment" />

From working with you on this app before I was able to make some tweaks for you.
What had to be done was to add new Views to fragment_navigation_drawer.xml and change the NavigationDrawerFragment to match up and include the changes.
Layout
<?xml version="1.0" encoding="utf-8"?>
<!-- the root view is now a LinearLayout, all other Views are children of this -->
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_height="match_parent"
android:layout_width="match_parent"
android:background="#cccc"
android:orientation="vertical">
<!-- a separate section to go above the list -->
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="10dp"
android:orientation="horizontal">
<!-- your image, you can set it later (see NavDrawerFrag) -->
<ImageView
android:id="#+id/nav_image"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="15dp"
android:src="#android:drawable/ic_menu_myplaces"/>
<!-- a bit of test or a title to go with it -->
<TextView
android:id="#+id/nav_text"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="match_parent"
android:gravity="center_vertical"
android:text="Default text"/>
</LinearLayout>
<!-- some divider thing -->
<View
android:layout_width="match_parent"
android:layout_height="2dp"
android:padding="20dp"
android:background="#000000"/>
<!-- your ListView is now a child View -->
<ListView
android:id="#+id/nav_listView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:choiceMode="singleChoice"
android:divider="#android:color/transparent"
android:dividerHeight="0dp"/>
</LinearLayout>
Fragment
// new class level members
private ImageView mDrawerImage;
private TextView mDrawerText;
// change the View inflation and extract the new child views
// also modifying the ListView to now be a child instead of the root View
#Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container,
Bundle savedInstanceState)
{
// need site names for list
siteNames = getActivity().getResources().getStringArray(R.array.site_names);
Log.d(TAG, "number of sites loaded: " + siteNames.length);
// inflate the parent view (the entire layout)
View view = inflater.inflate(R.layout.fragment_navigation_drawer, container, false);
// now grab the separate child views from inside it
mDrawerListView = (ListView) view.findViewById(R.id.nav_listView);
mDrawerImage = (ImageView) view.findViewById(R.id.nav_image);
mDrawerText = (TextView) view.findViewById(R.id.nav_text);
// configure the Views
mDrawerText.setText("Give it a name/title");
//mDrawerImage.setImageURI(...); // set your ImageView however you want, I just gave it one in XML
mDrawerListView.setOnItemClickListener(this);
mDrawerListView.setAdapter(new ArrayAdapter<String>(getActionBar().getThemedContext(),
android.R.layout.simple_list_item_1, android.R.id.text1, siteNames));
mDrawerListView.setItemChecked(mCurrentSelectedPosition, true);
// and return the inflated view up the stack
return view;
}

Android ImageView not showing in SherlockFragment

I'm trying to make an ImageView, in the Graphical view it shows up but when I run it on my device and the emulator the image doesn't show up. Here's my XML code.
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<ImageView
android:id="#+id/imageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:scaleType="fitXY"
android:src="#drawable/map_mockup" />
and here's my Fragment1 code (I am using Fragment1 as the Fragment to display this ImageView)
import com.actionbarsherlock.app.SherlockFragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.Toast;
import android.app.*;
import android.content.Intent;
public class Fragment1 extends SherlockFragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment1, container, false);
return rootView;
}
}
I hope this is enough, but if you need more code of the application I'll post it.
This is the first time I'm asking a question on Stack Overflow so if I do something wrong PLEASE tell me so I can correct it, so that in the future my questions layout is correct.
Here's the code for the activity I am adding the fragment to.
import android.app.Activity;
import android.os.Bundle;
import com.actionbarsherlock.app.SherlockFragmentActivity;
import com.actionbarsherlock.view.Menu;
import com.actionbarsherlock.view.MenuItem;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.app.Fragment;
import android.content.res.Configuration;
import android.support.v4.app.ActionBarDrawerToggle;
import android.support.v4.widget.DrawerLayout;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.support.v4.view.GravityCompat;
public class MainActivity extends SherlockFragmentActivity {
// Declare Variable
DrawerLayout mDrawerLayout;
ListView mDrawerList;
ActionBarDrawerToggle mDrawerToggle;
MenuListAdapter mMenuAdapter;
String[] title;
String[] subtitle;
int[] icon;
Fragment fragment1 = new Fragment1();
Fragment fragment2 = new Fragment2();
Fragment fragment3 = new Fragment3();
Fragment fragment4 = new Fragment4();
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.drawer_main);
// Generate title
title = new String[] { "Main", "Nick Honegger",
"Discounts", "About" };
// Generate subtitle
subtitle = new String[] { "Check nearby markets", "View your profile",
"Coupons and deals!", "Find out more!" };
// Generate icon
icon = new int[] { R.drawable.action_about, R.drawable.profile_pic,
R.drawable.collections_cloud, R.drawable.action_about };
// Locate DrawerLayout in drawer_main.xml
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
// Locate ListView in drawer_main.xml
mDrawerList = (ListView) findViewById(R.id.left_drawer);
// Set a custom shadow that overlays the main content when the drawer
// opens
mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow,
GravityCompat.START);
// Pass results to MenuListAdapter Class
mMenuAdapter = new MenuListAdapter(this, title, subtitle, icon);
// Set the MenuListAdapter to the ListView
mDrawerList.setAdapter(mMenuAdapter);
// Capture button clicks on side menu
mDrawerList.setOnItemClickListener(new DrawerItemClickListener());
// Enable ActionBar app icon to behave as action to toggle nav drawer
getSupportActionBar().setHomeButtonEnabled(true);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
// ActionBarDrawerToggle ties together the the proper interactions
// between the sliding drawer and the action bar app icon
mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout,
R.drawable.ic_drawer, R.string.drawer_open,
R.string.drawer_close) {
public void onDrawerClosed(View view) {
// TODO Auto-generated method stub
super.onDrawerClosed(view);
}
public void onDrawerOpened(View drawerView) {
// TODO Auto-generated method stub
super.onDrawerOpened(drawerView);
}
};
mDrawerLayout.setDrawerListener(mDrawerToggle);
if (savedInstanceState == null) {
selectItem(0);
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getSupportMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == android.R.id.home) {
if (mDrawerLayout.isDrawerOpen(mDrawerList)) {
mDrawerLayout.closeDrawer(mDrawerList);
} else {
mDrawerLayout.openDrawer(mDrawerList);
}
}
return super.onOptionsItemSelected(item);
}
// The click listener for ListView in the navigation drawer
private class DrawerItemClickListener implements
ListView.OnItemClickListener {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
selectItem(position);
}
}
private void selectItem(int position) {
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
// Locate Position
switch (position) {
case 0:
ft.replace(R.id.content_frame, fragment1);
break;
case 1:
ft.replace(R.id.content_frame, fragment2);
break;
case 2:
ft.replace(R.id.content_frame, fragment3);
break;
case 3:
ft.replace(R.id.content_frame, fragment4);
}
ft.commit();
mDrawerList.setItemChecked(position, true);
// Close drawer
mDrawerLayout.closeDrawer(mDrawerList);
}
#Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
// Sync the toggle state after onRestoreInstanceState has occurred.
mDrawerToggle.syncState();
}
#Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
// Pass any configuration change to the drawer toggles
mDrawerToggle.onConfigurationChanged(newConfig);
}
}
I've tried using Log.d and it shows that Fragment1 is being loaded. I'm stumped, I don't know what to do and am completely lost right here.
If it matters, the resolution for the PNG is 900x1429.

Two things I can think of.
First, I'm not sure if your layout code shows us the whole file or a snippet. If it's the whole file, you're missing a closing tag on the relativeLayout. If it's a snippet then ignore me.
Second, can you post the code for the Activity that you are adding this Fragment to?

Did you try to add the in the onCreateView instead of the xml?That would be the first thing I'd try.Btw I used the same tutorial as you did and consider yourself lucky,mine doesnt even show the image on my device -.-

Please would you try this:
ft.replace(android.R.id.content, fragment1, "frag1");
instead of
ft.replace(R.id.content_frame, fragment1);
?
If this doesn't change anything, I suggest you use Log.d to confirm that your fragment1 is actually being loaded.
Edit:
Good, then follow Arkan's line or reasoning or place a textview in your xml like this, to determine whether or not the xml is being loaded:
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="if you can see me the problem must be with my image"
/>