メイン アクティビティでサービスをバインドしようとしていますが、ヌル ポインター例外が発生します。サービスをバインドするために、onStart() および onStop() メソッドをアクティビティに追加しましたが、それ自体が null ポインター例外を引き起こしているようです。これは、コード行を慎重にコメントアウトすることで得た結論です。
明確にするために、さらに詳細を提供すると思います。
Null ポインタ例外は発生しません:
public class MainActivity extends Activity
implements NavigationDrawerFragment.NavigationDrawerCallbacks {
public VivaClientService VivaClient;
private static final String TAG = "Viva_MainActivity";
private Intent ClientIntent;
private ServiceConnection ClientConnect = new ServiceConnection(){
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
Log.d(TAG, "service connected");
LocalBinder binder = (LocalBinder)service;
VivaClient = binder.getService();
}
@Override
public void onServiceDisconnected(ComponentName name) {
Log.d(TAG, "service disconnected");
}
};
//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;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mNavigationDrawerFragment = (NavigationDrawerFragment)
getFragmentManager().findFragmentById(R.id.navigation_drawer);
mTitle = getTitle();
// Set up the drawer.
mNavigationDrawerFragment.setUp(
R.id.navigation_drawer,
(DrawerLayout) findViewById(R.id.drawer_layout));
ClientIntent = new Intent(this, VivaClientService.class);
}
/*
@Override
protected void onStart(){
//this.bindService(ClientIntent, ClientConnect, Context.BIND_AUTO_CREATE);
//this.startService(ClientIntent);
//JSONObject about = VivaClient.getAbout();
//System.out.println(about.toString());
}
@Override
protected void onStop(){
// this.stopService(ClientIntent);
// this.unbindService(ClientConnect);
}
*/
Null ポインター例外が発生します。
public class MainActivity extends Activity
implements NavigationDrawerFragment.NavigationDrawerCallbacks {
public VivaClientService VivaClient;
private static final String TAG = "Viva_MainActivity";
private Intent ClientIntent;
private ServiceConnection ClientConnect = new ServiceConnection(){
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
Log.d(TAG, "service connected");
LocalBinder binder = (LocalBinder)service;
VivaClient = binder.getService();
}
@Override
public void onServiceDisconnected(ComponentName name) {
Log.d(TAG, "service disconnected");
}
};
//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;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mNavigationDrawerFragment = (NavigationDrawerFragment)
getFragmentManager().findFragmentById(R.id.navigation_drawer);
mTitle = getTitle();
// Set up the drawer.
mNavigationDrawerFragment.setUp(
R.id.navigation_drawer,
(DrawerLayout) findViewById(R.id.drawer_layout));
ClientIntent = new Intent(this, VivaClientService.class);
}
@Override
protected void onStart(){
//this.bindService(ClientIntent, ClientConnect, Context.BIND_AUTO_CREATE);
//this.startService(ClientIntent);
//JSONObject about = VivaClient.getAbout();
//System.out.println(about.toString());
}
@Override
protected void onStop(){
// this.stopService(ClientIntent);
// this.unbindService(ClientConnect);
}
文字通り、2 つの唯一の違いは、含まれている場合は空である onStart メソッドと onStop メソッドが含まれていることです。なぜエラーが発生するのかわかりません。助けてください;_; ありがとう！