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Android Bluetooth Discovery API Isn't Working on Android 6.0

I've made an app, that is discovering nearby bluetooth devices and etc. I can get bluetooth adapter, open-close processes, get paired devices, discovering process. Everthing is fine but discovery process isn't working properly.
I tested my app on 5 different real devices. At the moment I realized I have a problem on Android version but I'm not sure about that.
My app's discovery process is working on,
Huawei P7 - Android Version: 4.4.2
Sony Xperia Z - Android Version: 5.1.1
Samsung Galaxy J3 - Android Version: 5.1.1
My app's discovery process isn't working on,
Samsung Galaxy S7 - Android Version: 6.0.1
Samsung Galaxy J7 - Android Version: 6.0.1
MainActivity.java
package com.sphinxlike.bluetoothexample;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Handler;
import android.os.Parcelable;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.Set;
import static java.lang.System.out;
public class MainActivity extends AppCompatActivity implements View.OnClickListener{
/* DECLERATIONS */
// Button
Button openBtn = null; // Open button
Button closeBtn = null; // Close button
Button listBtn = null; // Paired devices list button
Button searchBtn = null; // Discovery new devices button
// Bluetooth
private BluetoothAdapter mBluetoothAdapter = null; // Local bluetooth adapter variable
private static final int REQUEST_ENABLE_BT = 1; // Bluetooth open intent variable
String mDeviceName = null;
String mDeviceAddress = null;
public static String EXTRA_ADDRESS = "device_address";
// XML
TextView tvDeviceName = null; // To show local bluetooth device's name
TextView tvBluetoothState = null; // To show bluetooth state
ListView lvDeviceList = null; // To list paired devices or discovered devices
// Set, List, Array Adapter
private Set<BluetoothDevice> mPairedDevicesSet = null; // Paired devices Set
private Set<BluetoothDevice> mNewDevicesSet = null; // New devices Set
ArrayAdapter mPairedDevicesAdapter = null; // Paired devices array adapter
ArrayAdapter mNewDevicesAdapter = null; // New devices array adapter
ArrayList bluetoothDeviceList = null; // Listing bluetooth devices
private ArrayList<BluetoothDevice> btDeviceList = new ArrayList<BluetoothDevice>();
// Bluetooth State Updater
private Handler mHandler; // Loop in UI
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Initializes UI elements
tvDeviceName = (TextView)findViewById(R.id.deviceName);
tvBluetoothState = (TextView)findViewById(R.id.bluetoothState);
openBtn = (Button)findViewById(R.id.openBluetooth);
closeBtn = (Button)findViewById(R.id.closeBluetooth);
listBtn = (Button)findViewById(R.id.listBluetooth);
searchBtn = (Button)findViewById(R.id.searchBluetooth);
lvDeviceList = (ListView)findViewById(R.id.deviceList);
// Bluetooth adapter
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
// Button checks
openBtn.setOnClickListener((View.OnClickListener) this);
closeBtn.setOnClickListener((View.OnClickListener) this);
listBtn.setOnClickListener((View.OnClickListener) this);
searchBtn.setOnClickListener((View.OnClickListener) this);
// To update bluetooth state text view
tvBluetoothState.setText(String.valueOf(mBluetoothAdapter.getState()));
// If the phone does not support bluetooth adapter
if (mBluetoothAdapter == null) {
tvBluetoothState.setText("Your phone has not Bluetooth Adapter");
openBtn.setEnabled(false);
closeBtn.setEnabled(false);
listBtn.setEnabled(false);
searchBtn.setEnabled(false);
}
// Updater loop
mHandler = new Handler();
mHandler.post(mUpdate);
}
// Updater Loop
private Runnable mUpdate = new Runnable() {
public void run() {
getBluetoothState();
mHandler.postDelayed(this, 500);
}
};
// Button onClick method
public void onClick(View v) {
switch (v.getId()) {
case R.id.openBluetooth:
if (!mBluetoothAdapter.isEnabled()) {
Intent bluetoothAcIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(bluetoothAcIntent, REQUEST_ENABLE_BT);
} else {
Toast.makeText(getApplicationContext(), "Bluetooth is already open", Toast.LENGTH_SHORT).show();
}
break;
case R.id.closeBluetooth:
if (mBluetoothAdapter.isEnabled()) {
mBluetoothAdapter.disable();
} else {
Toast.makeText(getApplicationContext(), "Bluetooth is already close", Toast.LENGTH_SHORT).show();
}
break;
case R.id.listBluetooth:
pairedDevicesList();
break;
case R.id.searchBluetooth:
IntentFilter filter = new IntentFilter();
filter.addAction(BluetoothDevice.ACTION_FOUND);
filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_STARTED);
filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
registerReceiver(mBroadcastReceiver, filter);
mBluetoothAdapter.startDiscovery();
break;
}
};
#Override
public void onDestroy() {
unregisterReceiver(mBroadcastReceiver);
super.onDestroy();
}
private final BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
// Whenever a remote Bluetooth device is found
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
// Get the BluetoothDevice object from the Intent
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
Toast.makeText(getApplicationContext(), device.getName() + ":" + device.getAddress(), Toast.LENGTH_LONG).show();
// lvDeviceList.setAdapter(mPairedDevicesAdapter); // Set list view elements with adapter elements
}
}
};
// Show bluetooth state on UI
public void getBluetoothState() {
tvDeviceName.setText("Device Name: " + mBluetoothAdapter.getName());
switch(mBluetoothAdapter.getState()) { // Set bluetooth state text view
case 10: // STATE_OFF
tvBluetoothState.setText("Bluetooth is closed");
bluetoothDeviceList = new ArrayList(); // Initialize global array list variable that is declared
mPairedDevicesAdapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, bluetoothDeviceList); // Get array list and use in array adapter
lvDeviceList.setAdapter(mPairedDevicesAdapter); // Set list view elements with adapter elements
break;
case 11: // STATE_TURNING_ON
tvBluetoothState.setText("Bluetooth is opening");
break;
case 12: // STATE_ON
tvBluetoothState.setText("Bluetooth is opened");
break;
case 13: // STATE_TURNING_OFF
tvBluetoothState.setText("Bluetooth is closing");
break;
}
// If bluetooth adapter -> Set buttons
if (mBluetoothAdapter.isEnabled()) {
// Enable listing button
listBtn.setEnabled(true);
searchBtn.setEnabled(true);
} else {
// Disable listing button
listBtn.setEnabled(false);
searchBtn.setEnabled(false);
}
}
// Get paired device list and adapt to list view
public void pairedDevicesList()
{
if (!mBluetoothAdapter.isEnabled()) {
Toast.makeText(getApplicationContext(), "Open the Bluetooth", Toast.LENGTH_SHORT).show();
} else {
mPairedDevicesSet = mBluetoothAdapter.getBondedDevices(); // Get paired devices
bluetoothDeviceList = new ArrayList(); // Initialize global array list variable that is declared
if (mPairedDevicesSet.size()>0) {
for (BluetoothDevice bt : mPairedDevicesSet) { // for-each loop
mDeviceName = bt.getName();
mDeviceAddress = bt.getAddress();
bluetoothDeviceList.add(mDeviceName + "\n" + mDeviceAddress); // get the device name and add to array list object
}
} else if (mPairedDevicesSet.size()<=0){
Toast.makeText(getApplicationContext(), "No paired devices", Toast.LENGTH_SHORT).show();
}
mPairedDevicesAdapter = new ArrayAdapter(this,android.R.layout.simple_list_item_1, bluetoothDeviceList); // Get array list and use in array adapter
lvDeviceList.setAdapter(mPairedDevicesAdapter); // Set list view elements with adapter elements
}
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context="com.sphinxlike.bluetoothexample.MainActivity"
android:orientation="vertical">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Device Name"
android:id="#+id/deviceName"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:layout_marginTop="20dp">
<Button
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="wrap_content"
android:id="#+id/openBluetooth"
android:text="B. Open"
android:textAllCaps="false"
android:layout_gravity="center"
android:gravity="center"/>
<Button
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="wrap_content"
android:id="#+id/closeBluetooth"
android:text="B. Close"
android:textAllCaps="false"
android:layout_gravity="center"
android:gravity="center"/>
<Button
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="wrap_content"
android:id="#+id/listBluetooth"
android:text="List Paired"
android:textAllCaps="false"
android:layout_gravity="center"
android:gravity="center"/>
<Button
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="wrap_content"
android:id="#+id/searchBluetooth"
android:text="Search"
android:textAllCaps="false"
android:layout_gravity="center"
android:gravity="center"/>
</LinearLayout>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="20dp"
android:hint="Bluetooth State"
android:id="#+id/bluetoothState"
android:layout_gravity="center"
android:gravity="center"/>
<ListView
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:id="#+id/deviceList">
</ListView>
</LinearLayout>

Firstly, thanks #Tomasz Czura. I solved problem with multiple runtime permission request.
Android Developer 6.0 Changes page says:
To access the hardware identifiers of nearby external devices via Bluetooth and Wi-Fi scans, your app must now have the ACCESS_FINE_LOCATION or ACCESS_COARSE_LOCATION permissions:
So, I added permission to AndroidManifest.XML:
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
then I rearranged my activity like this:
public class MainActivity extends AppCompatActivity {
...
int ACTION_REQUEST_MULTIPLE_PERMISSION = 1; // Any number
#Override
protected void onCreate(Bundle savedInstanceState) {
...
int pCheck = this.checkSelfPermission("Manifest.permission.ACCESS_FINE_LOCATION");
pCheck += this.checkSelfPermission("Manifest.permission.ACCESS_COARSE_LOCATION");
pCheck += this.checkSelfPermission("Manifest.permission.BLUETOOTH_ADMIN");
pCheck += this.checkSelfPermission("Manifest.permission.BLUETOOTH");
if (pCheck != 0) {
this.requestPermissions(new String[]{Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION,
Manifest.permission.BLUETOOTH_ADMIN, Manifest.permission.BLUETOOTH}, ACTION_REQUEST_MULTIPLE_PERMISSION);
}
}
}
It worked.

You have to ask for Bluetooth permissions at run time in Android 6.0 -
ActivityCompat.requestPermissions(..)

To stop a Background Music from 1 activity to another using a checkbox?

My Main Activity has a background music, and I want to stop it whenever I can, through a checkbox. I have the codes already in order to set the background music into the Main activity, and it works perfect. The problem is that I want to stop a specific song from another activity using a CheckBox. I configured the checkbox, however, it does not work. Somehelp is really appreciated.
PD: The comunication between these two activities work well. It is the checkbox that does not work
Here are my codes used.
MainActivity.java
`
public class MainActivity extends Activity implements View.OnClickListener {
MediaPlayer bkgrdmsc;
private int lmusic_checked = SettingsActivity.music_checked;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (lmusic_checked == 0){
bkgrdmsc = MediaPlayer.create(MainActivity.this, R.raw.backgroundmusic);
bkgrdmsc.setLooping(true);
bkgrdmsc.start();
}
#Override
protected void onPause() {
if (lmusic_checked == 0){
bkgrdmsc.release();
}
SettingsActivity.music_checked =0;
super.onPause();
bkgrdmsc.release();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
//inflate the menu; this adds items to the action bar if this is present
super.onCreateOptionsMenu(menu);
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_settings) {
Intent s_intent = new Intent(this, SettingsActivity.class);
startActivity(s_intent);
return true;
}
else if (id == R.id.logo_home){
Intent t_intent = new Intent(this, Twitter.class);
startActivity(t_intent);
return true;
}
return super.onOptionsItemSelected(item);
}
activity_settings.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:weightSum="1">
<TextView
android:layout_width="271dp"
android:layout_height="77dp"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="#string/c_general"
android:id="#+id/textView"
android:layout_gravity="center_vertical"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="57dp"
android:textSize="26dp" />
<CheckBox
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/turn_on_music"
android:id="#+id/CheckBox"
android:layout_below="#+id/textView"
android:layout_centerHorizontal="true"
android:checked="false"
android:singleLine="false"
android:textColor="#000000" />
</RelativeLayout>
SettingsActivity.java
package com.example.json.publicomidas;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.CheckBox;
import android.widget.CompoundButton;
public class SettingsActivity extends Activity {
public static int music_checked= 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.action_settings);
music_off();
}
public void music_off(){
CheckBox checkBox1 = (CheckBox) findViewById(R.id.CheckBox);
checkBox1.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
if (buttonView.isChecked()) {
music_checked = 1;
} else {
music_checked = 0;
}
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
//inflate the menu; this adds items to the action bar if this is present
super.onCreateOptionsMenu(menu);
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu_settings, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.home) {
Intent s_intent = new Intent(this, MainActivity.class);
startActivity(s_intent);
return true;
}
return super.onOptionsItemSelected(item);
}
}

Man, you should not do it this way... You cannot make two activities communicate each other with a static field :) When you change the value of music_checked in SetttingsActivity this changes nothing in the MainActivity.
My advice is to create a Service that runs the music. Both the activities should properly bind to the service and manipulate the music playback.
Update1
The communication you have implemented using this static field works only in one direction. You cannot stop the music by changing the music_checked property. It is a property of the SettingsActivity class and the MainActivity instance knows nothing about its state.
The proper way to implement this is using a Service that plays the music. It is not correct to play the music from an Activity if you want the playback to continue after the activity is paused/stoped. Create a bound service and bind each activity to the service in their onResume or onStart method (and unbind in onPause/onStop). By binding to the service you receive an object that exposes some API (you have to define this API and create the object according to the functionality you want to have). Using this API you can control the service from both the activities.
I'll advise you to read a bit more about activities and services in android and their lifecycle.

InAppBilling crashes on startup

I'm trying to make an app that I can get a simple implementation of in app purchases. I've been falling this guide http://www.techotopia.com/index.php/Integrating_Google_Play_In-app_Billing_into_an_Android_Application_%E2%80%93_A_Tutorial
but it's fraught with probably outdated information and neglects to include all the names of the packages you need to download from the SDK manager.
The main errors I had from this program were seemingly reference errors like I had not imported a certain library or compatibility files were missing. I managed to resolve all of them in eclipse and there are no errors when I run the code but trying it on a device or in the VM, the app crashes when I try to run it there.
I excluded the key you need for the google play connection for obvious reasons.
package com.a.inappbilling;
import com.a.inappbilling.util.IabHelper;
import com.a.inappbilling.util.IabResult;
import com.a.inappbilling.util.Inventory;
import com.a.inappbilling.util.Purchase;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.os.Build;
import android.widget.Button;
import android.content.Intent;
import android.util.Log;
public class InAppBillingActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_in_app_billing);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).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.in_app_billing, 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();
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 {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_in_app_billing,
container, false);
return rootView;
}
}
private Button clickButton;
private Button buyButton;
#Override
protected void onStart() {
super.onStart();
buyButton = (Button)findViewById(R.id.buyButton);
clickButton = (Button)findViewById(R.id.clickButton);
clickButton.setEnabled(false);
String base64EncodedPublicKey =
"key here";
mHelper = new IabHelper(this, base64EncodedPublicKey);
mHelper.startSetup(new
IabHelper.OnIabSetupFinishedListener() {
public void onIabSetupFinished(IabResult result)
{
if (!result.isSuccess()) {
Log.d(TAG, "In-app Billing setup failed: " +
result);
} else {
Log.d(TAG, "In-app Billing is set up OK");
}
}
});
}
public void buttonClicked (View view)
{
clickButton.setEnabled(false);
buyButton.setEnabled(true);
}
private static final String TAG = "com.a.inappbilling";
IabHelper mHelper;
}

Add permission to your Manifest file
<uses-permission android:name="com.android.vending.BILLING" />
also add to your Manifest file under the Application node
<meta-data
android:name="com.google.android.gms.version"
android:value="#integer/google_play_services_version" />
Also just verify you have added InAppBillingActivity.java to your Manifest file.

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: null pointer exception when trying to set any property of button

i have checked everything in this but still i am getting a null pointer exception . whenever i am trying to change the properties of button in java file, app stop working and logcat showing null pointer exception. plzz help me out
here is my code
package com.example.rapid_finger;
import java.util.Random;
import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.app.Activity;
import android.os.Build;
import android.os.Bundle;
import android.support.v4.app.NavUtils;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
public class PlayScreen extends Activity {
#SuppressLint("NewApi")
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Random rand = new Random();
int data = rand.nextInt(99);
String str = Integer.toString(data);
Button b = (Button) findViewById(R.id.b1);
b.setText(str);
setContentView(R.layout.activity_play_screen);
// Show the Up button in the action bar.
setupActionBar();
}
/**
* Set up the {#link android.app.ActionBar}, if the API is available.
*/
#TargetApi(Build.VERSION_CODES.HONEYCOMB)
private void setupActionBar() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
getActionBar().setDisplayHomeAsUpEnabled(true);
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.play_screen, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
// This ID represents the Home or Up button. In the case of this
// activity, the Up button is shown. Use NavUtils to allow users
// to navigate up one level in the application structure. For
// more details, see the Navigation pattern on Android Design:
//
// http://developer.android.com/design/patterns/navigation.html#up- vs-back
//
NavUtils.navigateUpFromSameTask(this);
return true;
}
return super.onOptionsItemSelected(item);
}
}
and here is my xml file
<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"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context=".PlayScreen" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/scores" />
<Button
android:id="#+id/b1"
android:background="#drawable/back"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</RelativeLayout>

You did findViewById before you setContentView.
setContentView should come first

#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_play_screen);
Random rand = new Random();
int data = rand.nextInt(99);
String str = Integer.toString(data);
Button b = (Button) findViewById(R.id.b1);
b.setText(str);
// Show the Up button in the action bar.
setupActionBar();
}
put setContentView(R.layout.activity_play_screen); after super.onCreate(savedInstanceState);

// replace this code
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_play_screen);
Random rand = new Random();
int data = rand.nextInt(99);
String str = Integer.toString(data);
Button b = (Button) findViewById(R.id.b1);
b.setText(str);
// Show the Up button in the action bar.
setupActionBar();
}