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WebView in fragments

I am creating an application for android and I need to put a webview in a fragment but I have tried a lot of codes and none works for me. I need help
This is the code of my fragment When I run the application with that code in the fragment is when it stops.
I do not know if it will be for the code that brings the default fragment since all the menu sections work but when I enter this one that has a webview it stops
package org.protectorabaix;
import android.content.Context;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
/**
* A simple {#link Fragment} subclass.
* Activities that contain this fragment must implement the
* {#link ListadoAnimales.OnFragmentInteractionListener} interface
* to handle interaction events.
* Use the {#link ListadoAnimales#newInstance} factory method to
* create an instance of this fragment.
*/
public class ListadoAnimales extends Fragment {
public WebView mWebView;
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private OnFragmentInteractionListener mListener;
public ListadoAnimales() {
// Required empty public constructor
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* #param param1 Parameter 1.
* #param param2 Parameter 2.
* #return A new instance of fragment ListadoAnimales.
*/
// TODO: Rename and change types and number of parameters
public static ListadoAnimales newInstance(String param1, String param2) {
ListadoAnimales fragment = new ListadoAnimales();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v=inflater.inflate(R.layout.fragment_listado_animales, container, false);
mWebView = (WebView) v.findViewById(R.id.listado);
mWebView.loadUrl("https://google.com");
// Enable Javascript
WebSettings webSettings = mWebView.getSettings();
webSettings.setJavaScriptEnabled(true);
// Force links and redirects to open in the WebView instead of in a browser
mWebView.setWebViewClient(new WebViewClient());
return v;
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof OnFragmentInteractionListener) {
mListener = (OnFragmentInteractionListener) context;
} else {
throw new RuntimeException(context.toString()
+ " must implement OnFragmentInteractionListener");
}
}
#Override
public void onDetach() {
super.onDetach();
mListener = null;
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
void onFragmentInteraction(Uri uri);
}
}

Calling getView on a Fragment returns null

So as you can see in the onCreate method i call getView on the 0th fragment in the "fragments" list. It returns null. I've tried putting a timer in the code and have it run every second and check if the view is null. And on the second tick of the timer the view is NOT null. Basically
MainActivity.java
package com.axinite.standapp;
import android.graphics.Color;
import android.os.CountDownTimer;
import android.os.Handler;
import android.support.annotation.Nullable;
import android.support.design.widget.TabLayout;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.os.Bundle;
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.view.ViewParent;
import android.widget.EditText;
import android.widget.NumberPicker;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
import java.util.Timer;
import java.util.TimerTask;
import java.util.Vector;
public class MainActivity extends AppCompatActivity {
int i = 0;
/**
* The {#link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a
* {#link FragmentPagerAdapter} derivative, which will keep every
* loaded fragment in memory. If this becomes too memory intensive, it
* may be best to switch to a
* {#link android.support.v4.app.FragmentStatePagerAdapter}.
*/
private SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {#link ViewPager} that will host the section contents.
*/
private ViewPager mViewPager;
int standUpSeconds = 4000;
List<android.support.v4.app.Fragment> fragments = new Vector<android.support.v4.app.Fragment>();
NumberPicker SUPickerH;
NumberPicker SUPickerM;
NumberPicker SUPickerS;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
fragments.add(Fragment.instantiate(this, BlankFragment.class.getName()));
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager(), fragments);
mViewPager = (ViewPager) findViewById(R.id.container);
mViewPager.setAdapter(mSectionsPagerAdapter);
final TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(mViewPager);
tabLayout.setSelectedTabIndicatorColor(Color.WHITE);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
final int[] ICONS = new int[] {
R.drawable.walking,
R.drawable.iris
};
for (int i=0; i < tabLayout.getTabCount(); i++)
{
tabLayout.getTabAt(i).setIcon(getDrawable(ICONS[i]));
}//endfor)
View view = ((BlankFragment) fragments.get(0)).getView();
if(view != null) {
TextView tv = (TextView) view.findViewById(R.id.glupost);
tv.setText("dasdas");
//Toast.makeText(getApplicationContext(), ((Fragment) fragments.get(0)).toString(), Toast.LENGTH_SHORT).show();
}
}
void Setup() {
}
#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_main, 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);
}
/**
* A {#link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
List<Fragment> fragments;
public SectionsPagerAdapter(FragmentManager fm, List<Fragment> fragments) {
super(fm);
this.fragments = fragments;
}
#Override
public Fragment getItem(int position) {
return fragments.get(position);
}
#Override
public int getCount() {
// Show 3 total pages.
return fragments.size();
}
#Override
public CharSequence getPageTitle(int position) {
return "";
}
}
}
BlankFragment.java
package com.axinite.standapp;
import android.app.Activity;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
/**
* A simple {#link Fragment} subclass.
* Activities that contain this fragment must implement the
* {#link BlankFragment.OnFragmentInteractionListener} interface
* to handle interaction events.
* Use the {#link BlankFragment#newInstance} factory method to
* create an instance of this fragment.
*/
public class BlankFragment extends Fragment {
protected View mView;
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private OnFragmentInteractionListener mListener;
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* #param param1 Parameter 1.
* #param param2 Parameter 2.
* #return A new instance of fragment BlankFragment.
*/
// TODO: Rename and change types and number of parameters
public static BlankFragment newInstance(String param1, String param2) {
BlankFragment fragment = new BlankFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
public BlankFragment() {
// Required empty public constructor
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_blank, container, false);
mView = view;
return view;
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mListener = (OnFragmentInteractionListener) activity;
} catch (ClassCastException e) {
}
}
#Override
public void onDetach() {
super.onDetach();
mListener = null;
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p/>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
public void onFragmentInteraction(Uri uri);
}
}

The typical method for an Activity to communicate with its Fragments is as follows:
MyFragment frag = (MyFragment) getFragmentManager().findFragmentById(R.id.container_of_fragment);
frag.getMyTextView().setText("New text");
or (often preferred IMO)
MyFragment frag = (MyFragment) getFragmentManager().findFragmentByTag("fragment_tag_string_value");
frag.getMyTextView().setText("New text");
This is rendered more difficult with a ViewPager however, as the "id" of the container is the ViewPager itself, which contains multiple fragments. In addition, there isn't an in built adapter mechanism (that I'm aware of) to set tags to fragments.
There are two methods I can think of that circumvent this. First, you can use an EventBus, such as GreenRobot's EventBus, or LocalBroadcastManager from the Android API. GreenRobot's EventBus is also the recommended technique in the answer to this similar question.
An alternative would leverage the fact that a Fragment always has a reference to its host Activity, which means the Fragment could request the text from the Activity via an interface, which returns it to the Fragment:
public class MainActivity implements FragmentOne.Callbacks {
//...
#Override
public String requestTextViewString() {
return "Text to send to Fragment"
}
And inside your hypothetical FragmentOne:
public class FragmentOne extends Fragment {
private Callbacks mCallback;
private TextView mTextView;
public interface Callbacks {
String requestTextViewString();
}
#Override
public void onAttach(Activity activity) {
if (activity instanceof Callbacks) {
mCallback = (Callbacks) activity;
}
}
/*
*Later in your Fragment, when you want to get text from your MainActivity
* i.e. in onCreateView()
*/
mTextView.setText(mCallback.requestTextViewString());
Edit: Also keep in mind that attempting to access your Fragment from onCreate() in your Activity is likely to result in a NullPointerException. This diagram shows both lifecycles alongside each other. This shouldn't be a problem however, as anything required during the "set-up" lifecycle events of the Fragment can just be passed as an argument in the Fragment's newInstance() method:
public class FragmentOne extends Fragment {
private static final String KEY = "text_for_text_view_key";
public static FragmentOne newInstance(String textForTextView) {
Bundle args = new Bundle();
FragmentOne frag = new FragmentOne();
args.putString(KEY, textForTextView);
frag.setArguments(args);
return frag;
}
//And when required...
mTextView.setText(getArguments().getString(KEY));

Error:(17, 21) error: no suitable method found for add(int, ExampleItemFragment)

I'm using Android Studio. I'm trying to develop an app where one fragment holds a list, and tapping an item displays another fragment with details. I built the list, following the tutorial available at: https://www.airpair.com/android/list-fragment-android-studio
I was planning on taking the code apart again after seeing how it ran. However, when I tried to run it (at step 6, where the basic list should be functioning), I got the error:
Error:(17, 21) error: no suitable method found for add(int,ExampleItemFragment)
method FragmentTransaction.add(Fragment,String) is not applicable
(argument mismatch; int cannot be converted to Fragment)
method FragmentTransaction.add(int,Fragment) is not applicable
(argument mismatch; ExampleItemFragment cannot be converted to Fragment)
in
package com.example.brittany.fragmentlistexample;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new ExampleItemFragment())
.commit();
}
}
#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_main, 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);
}
}
Where & how should I implement this .add() method, or should I do something to the object I'm passing in order to make an inherited .add() accept it? The class ExampleItemFragment already extends Fragment.
ExampleItemFragment's code (mostly untouched from the default code):
package com.example.brittany.fragmentlistexample;
import android.app.Activity;
import android.os.Bundle;
import android.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;
import android.widget.TextView;
import android.widget.Toast;
import com.example.brittany.fragmentlistexample.dummy.DummyContent;
import java.util.ArrayList;
import java.util.List;
public class ExampleItemFragment extends Fragment implements AbsListView.OnItemClickListener {
private List exampleListItemList; // at the top of your fragment list
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private OnFragmentInteractionListener mListener;
/**
* The fragment's ListView/GridView.
*/
private AbsListView mListView;
/**
* The Adapter which will be used to populate the ListView/GridView with
* Views.
*/
private ListAdapter mAdapter;
// TODO: Rename and change types of parameters
public static ExampleItemFragment newInstance(String param1, String param2) {
ExampleItemFragment fragment = new ExampleItemFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
/**
* Mandatory empty constructor for the fragment manager to instantiate the
* fragment (e.g. upon screen orientation changes).
*/
public ExampleItemFragment() {
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
exampleListItemList = new ArrayList();
exampleListItemList.add(new ExampleListItem("Example 1"));
exampleListItemList.add(new ExampleListItem("Example 2"));
exampleListItemList.add(new ExampleListItem("Example 3"));
mAdapter = new ExampleListAdapter(getActivity(), exampleListItemList);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
// TODO: Change Adapter to display your content
mAdapter = new ArrayAdapter<DummyContent.DummyItem>(getActivity(),
android.R.layout.simple_list_item_1, android.R.id.text1, DummyContent.ITEMS);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_exampleitem, container, false);
// Set the adapter
mListView = (AbsListView) view.findViewById(android.R.id.list);
((AdapterView<ListAdapter>) mListView).setAdapter(mAdapter);
// Set OnItemClickListener so we can be notified on item clicks
mListView.setOnItemClickListener(this);
return view;
}
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mListener = (OnFragmentInteractionListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnFragmentInteractionListener");
}
}
#Override
public void onDetach() {
super.onDetach();
mListener = null;
}
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
ExampleListItem item = (ExampleListItem)this.exampleListItemList.get(position);
Toast.makeText(getActivity(), item.getItemTitle() + " Clicked!"
, Toast.LENGTH_SHORT).show();
if (null != mListener) {
// Notify the active callbacks interface (the activity, if the
// fragment is attached to one) that an item has been selected.
mListener.onFragmentInteraction(DummyContent.ITEMS.get(position).id);
}
}
/**
* The default content for this Fragment has a TextView that is shown when
* the list is empty. If you would like to change the text, call this method
* to supply the text it should use.
*/
public void setEmptyText(CharSequence emptyText) {
View emptyView = mListView.getEmptyView();
if (emptyView instanceof TextView) {
((TextView) emptyView).setText(emptyText);
}
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p/>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
public void onFragmentInteraction(String id);
}
}

You have to import the Fragment from the support library, not from the android.widget. Use import android.support.v4.app.Fragment; in your fragment.

BlankFragment.newInstance("","") - Required: android.support.v4.app.Fragment - when using android.app.Fragment

I am using Android Studio 1.2.1.1 to learn Android programming. I created a new Project with Fragments and a BlankFragments-class.
But when I use the newInstance(String param1, String param2)-Method of the BlankFragment-Class in the MainActivity-Class, the compiler tells me android.support.v4.app.Fragment is required.
The problem is, the new BlankFragment-Class uses android.app.Fragment and the MainActivity uses android.support.v4.app.Fragment. But if I change the import in the MainActivity-Class I keep getting new Errors.
This is really frustrating, because these are the default structures in Android Studio as far as I know.
Main Activity:
package de.immozukunft.scouttools;
import java.util.Locale;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.app.FragmentPagerAdapter;
import android.os.Bundle;
import android.support.v4.view.ViewPager;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class MainActivity extends ActionBarActivity implements ActionBar.TabListener {
/**
* The {#link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a
* {#link FragmentPagerAdapter} derivative, which will keep every
* loaded fragment in memory. If this becomes too memory intensive, it
* may be best to switch to a
* {#link android.support.v4.app.FragmentStatePagerAdapter}.
*/
SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {#link ViewPager} that will host the section contents.
*/
ViewPager mViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Set up the action bar.
final ActionBar actionBar = getSupportActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Create the adapter that will return a fragment for each of the three
// primary sections of the activity.
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
// When swiping between different sections, select the corresponding
// tab. We can also use ActionBar.Tab#select() to do this if we have
// a reference to the Tab.
mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
#Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
});
// For each of the sections in the app, add a tab to the action bar.
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
// Create a tab with text corresponding to the page title defined by
// the adapter. Also specify this Activity object, which implements
// the TabListener interface, as the callback (listener) for when
// this tab is selected.
actionBar.addTab(
actionBar.newTab()
.setText(mSectionsPagerAdapter.getPageTitle(i))
.setTabListener(this));
}
}
#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_main, 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);
}
#Override
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
// When the given tab is selected, switch to the corresponding page in
// the ViewPager.
mViewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
#Override
public void onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
/**
* A {#link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a PlaceholderFragment (defined as a static inner class below).
switch (position){
case 0:
return PlaceholderFragment.newInstance(position + 1);
break;
case 1:
return BlankFragment.newInstance("","");
break;
case 2:
return PlaceholderFragment.newInstance(position + 1);
break;
default:
return PlaceholderFragment.newInstance(position + 1);
}
}
#Override
public int getCount() {
// Show 3 total pages.
return 3;
}
#Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return getString(R.string.title_section1).toUpperCase(l);
case 1:
return getString(R.string.title_section2).toUpperCase(l);
case 2:
return getString(R.string.title_section3).toUpperCase(l);
}
return null;
}
}
/**
* 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_main, container, false);
return rootView;
}
}
}
BlankFragments:
package de.immozukunft.scouttools;
import android.app.Activity;
import android.net.Uri;
import android.os.Bundle;
import android.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
/**
* A simple {#link Fragment} subclass.
* Activities that contain this fragment must implement the
* {#link BlankFragment.OnFragmentInteractionListener} interface
* to handle interaction events.
* Use the {#link BlankFragment#newInstance} factory method to
* create an instance of this fragment.
*/
public class BlankFragment extends Fragment {
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private OnFragmentInteractionListener mListener;
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* #param param1 Parameter 1.
* #param param2 Parameter 2.
* #return A new instance of fragment BlankFragment.
*/
// TODO: Rename and change types and number of parameters
public static BlankFragment newInstance(String param1, String param2) {
BlankFragment fragment = new BlankFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
public BlankFragment() {
// Required empty public constructor
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_blank, container, false);
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mListener = (OnFragmentInteractionListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnFragmentInteractionListener");
}
}
#Override
public void onDetach() {
super.onDetach();
mListener = null;
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p/>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
public void onFragmentInteraction(Uri uri);
}
}

I can't just replace android.support.v4.app.Fragment with android.app.Fragment in the MainActivity
Yes, you can. Replace:
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.app.FragmentPagerAdapter;
with:
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.support.v13.app.FragmentPagerAdapter;
Note that the last line will require you to be depending upon support-v13 in your build.gradle file; if you have a dependency on support-v4 instead, replace that with support-v13.
You will also need to replace getSupportFragmentManager() with getFragmentManager() where it appears in your code. There may be a few other edits besides those, but that should get you close.
Here is sample project that uses native API Level 11+ fragments with a ViewPager.
But if I change the import in the MainActivity-Class I keep getting new Errors.
Never make a statement like that in a Stack Overflow question — or any support situation — without explaining what the errors are.

cannot find symbol method findPreference(String)

I have hare one fragment where I try to get my set value from my list, buy it don't find findPreference method , why?
package com.cetabo.trackingpoint;
import android.app.Activity;
import android.content.Context;
import android.content.SharedPreferences;
import android.content.res.Resources;
import android.os.Bundle;
import android.preference.ListPreference;
import android.preference.Preference;
import android.preference.PreferenceManager;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.TextView;
import java.util.Timer;
import java.util.TimerTask;
import com.cetabo.trackingpoint.dummy.DummyContent;
import com.cetabo.trackingpoint.util.DetectionLocation;
import java.util.Date;
/**
* A fragment representing a list of Items.
* <p/>
* Large screen devices (such as tablets) are supported by replacing the ListView
* with a GridView.
* <p/>
* Activities containing this fragment MUST implement the {#link OnFragmentInteractionListener}
* interface.
*/
public class PlacesFragment extends Fragment implements AbsListView.OnItemClickListener {
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private OnFragmentInteractionListener mListener;
/**
* The fragment's ListView/GridView.
*/
private AbsListView mListView;
ImageView imageView;
/**
* The Adapter which will be used to populate the ListView/GridView with
* Views.
*/
private ListAdapter mAdapter;
// TODO: Rename and change types of parameters
public static PlacesFragment newInstance(String param1, String param2) {
PlacesFragment fragment = new PlacesFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
/**
* Mandatory empty constructor for the fragment manager to instantiate the
* fragment (e.g. upon screen orientation changes).
*/
public PlacesFragment() {
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
// TODO: Change Adapter to display your content
// mAdapter = new ArrayAdapter<>(getActivity(), android.R.layout.simple_list_item_1, android.R.id.text1, DummyContent.ITEMS);
}
String[] test ={"test","test"};
String text = "Central Park";
Date data = new Date();
//---HERE IS MY PROBLEM---
ListPreference listPreference = (ListPreference) findPreference("sync_frequency");
//------------------------
// Resources res = getResources();
// String[] time = res.getStringArray(R.array.pref_example_list_values);
// ArrayAdapter<String> adapter = ArrayAdapter.createFromResource(this, R.array.pref_sync_frequency_values, android.R.layout.simple_spinner_item);
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_place, container, false);
Context ctx = view.getContext();
DetectionLocation detectionLocation = new DetectionLocation(ctx);
CustomListAdapter adapter=new CustomListAdapter(getActivity(),test,String.valueOf(detectionLocation.getLongitude()+" "+detectionLocation.getLatitude()),data);
mListView = (AbsListView) view.findViewById(android.R.id.list);
mListView.setAdapter(adapter);
// Set OnItemClickListener so we can be notified on item clicks
mListView.setOnItemClickListener(this);
return view;
}
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
// try {
// mListener = (OnFragmentInteractionListener) activity;
// } catch (ClassCastException e) {
// throw new ClassCastException(activity.toString()
// + " must implement OnFragmentInteractionListener");
// }
}
#Override
public void onDetach() {
super.onDetach();
mListener = null;
}
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
if (null != mListener) {
// Notify the active callbacks interface (the activity, if the
// fragment is attached to one) that an item has been selected.
mListener.onFragmentInteraction(DummyContent.ITEMS.get(position).id);
}
}
/**
* The default content for this Fragment has a TextView that is shown when
* the list is empty. If you would like to change the text, call this method
* to supply the text it should use.
*/
public void setEmptyText(CharSequence emptyText) {
View emptyView = mListView.getEmptyView();
if (emptyView instanceof TextView) {
((TextView) emptyView).setText(emptyText);
}
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p/>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
public void onFragmentInteraction(String id);
}
}

Because,
findPreference() is method from PreferenceFragment if you are using API Level 11+ devices. Or / Otherwise, It would be from PreferenceActivity.
For more info look at http://developer.android.com/reference/android/preference/PreferenceActivity.html

You can access preferences from within a fragment by creating a SharedPreference object in your onAttach method.
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
SharedPreferences sharedPrefs = PreferenceManager.getDefaultSharedPreferences(activity);
String myPref = sharedPrefs.getString("sync_frequency", "");
}