Ich habe Projekt mit dem Fragment und mit Navigationsleiste enthält die Navigationsleiste 4 Menü: 1. Empfehlung 2. LuxWoher weiß man, welches Fragment in Android sichtbar ist?
Das Problem ist, wenn ich in Lux Menü-Taste i dann zurückgedrückt es auf die Empfehlung gehen sollte (Welches ist das Hauptmenü). Aber wenn ich in der Empfehlung und ich drückte Taste, sollte es die App zu schließen, wie zu erkennen, ob ich im Empfehlungsmenü war?
Hauptaktivität
public class MainActivity extends AppCompatActivity{
DrawerLayout mDrawerLayout;
NavigationView mNavigationView;
FragmentManager mFragmentManager;
FragmentTransaction mFragmentTransaction;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
/**
*Setup the DrawerLayout and NavigationView
*/
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawerLayout);
mNavigationView = (NavigationView) findViewById(R.id.shitstuff) ;
/**
* Lets inflate the very first fragment
* Here , we are inflating the TabFragment as the first Fragment
*/
mFragmentManager = getSupportFragmentManager();
mFragmentTransaction = mFragmentManager.beginTransaction();
mFragmentTransaction.replace(R.id.containerView,new Recommendation()).commit();
/**
* Setup click events on the Navigation View Items.
*/
mNavigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(MenuItem menuItem) {
mDrawerLayout.closeDrawers();
if (menuItem.getItemId() == R.id.nav_item_lux_level_recomen) {
FragmentTransaction fragmentTransaction = mFragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.containerView,new Recommendation()).commit();
}
if (menuItem.getItemId() == R.id.nav_item_room_index_calc) {
FragmentTransaction xfragmentTransaction = mFragmentManager.beginTransaction();
xfragmentTransaction.replace(R.id.containerView,new RoomIndex()).commit();
}
if (menuItem.getItemId() == R.id.nav_item_utilization_factor_calc) {
FragmentTransaction xfragmentTransaction = mFragmentManager.beginTransaction();
xfragmentTransaction.replace(R.id.containerView,new UtilizationFactorCalculator()).commit();
}
if (menuItem.getItemId() == R.id.nav_item_conversions) {
FragmentTransaction xfragmentTransaction = mFragmentManager.beginTransaction();
xfragmentTransaction.replace(R.id.containerView,new Conversion()).commit();
}
if (menuItem.getItemId() == R.id.nav_item_lux) {
FragmentTransaction xfragmentTransaction = mFragmentManager.beginTransaction();
xfragmentTransaction.replace(R.id.containerView,new LuxSensor()).commit();
}
return false;
}
});
/**
* Setup Drawer Toggle of the Toolbar
*/
android.support.v7.widget.Toolbar toolbar = (android.support.v7.widget.Toolbar) findViewById(R.id.toolbar);
ActionBarDrawerToggle mDrawerToggle = new ActionBarDrawerToggle(this,mDrawerLayout, toolbar,R.string.app_name,
R.string.app_name);
mDrawerLayout.setDrawerListener(mDrawerToggle);
mDrawerToggle.syncState();
}
Lux Menü
public class LuxSensor extends Fragment {
TextView textLIGHT_available, textLIGHT_reading;
FragmentManager mFragmentManager;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View x = inflater.inflate(R.layout.lux_sensor,null);
textLIGHT_reading
= (TextView)x.findViewById(R.id.LIGHT_reading);
SensorManager mySensorManager = (SensorManager)getActivity().getSystemService(Context.SENSOR_SERVICE);
Sensor LightSensor = mySensorManager.getDefaultSensor(Sensor.TYPE_LIGHT);
if(LightSensor != null){
mySensorManager.registerListener(
LightSensorListener,
LightSensor,
SensorManager.SENSOR_DELAY_NORMAL);
}else{
textLIGHT_available.setText("Sensor.TYPE_LIGHT NOT Available");
}
FragmentManager fm = getFragmentManager();
return x;
}
private final SensorEventListener LightSensorListener
= new SensorEventListener(){
@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
// TODO Auto-generated method stub
}
@Override
public void onSensorChanged(SensorEvent event) {
if(event.sensor.getType() == Sensor.TYPE_LIGHT){
textLIGHT_reading.setText(event.values[0]+" LUX");
}
}
};
Ich bin sicher, Sie schauen Sie sich um Lösungen haben würde . Sie finden die Lösung [hier] (http://stackoverflow.com/questions/10024739/how-to-determine-when-fragment-becomes-visible-in-viewpager) und [hier] (http://stackoverflow.com)/questions/18375288/fragment-lifecycle-welche-Methode-wird-aufgerufen-show-hide). – Geek