I have one NavigationActivity and MainActivity, in NavigationActivity i'm using navigation drawer and MainActivity extend NavigationActivity in MainActivity i'm using Theme.AppCompat.Light.NoActionBar and also usning Toolbar but i'm getting null pointer exception getsupportActionbar() i have tried the following code to do that
import android.content.Intent;
import android.content.res.Configuration;
import android.support.annotation.NonNull;
import android.support.design.widget.NavigationView;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.FrameLayout;
import com.toolbarimport.AboutActivity;
import com.toolbarimport.ExchangeActivity;
import com.toolbarimport.R;
public class NavigationActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {
private FrameLayout mainView;
private NavigationView navigation_view;
private DrawerLayout mDrawerLayout;
private ActionBarDrawerToggle mDrawerToggle;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
super.setContentView(R.layout.activity_navigation);
mainView = (FrameLayout) findViewById(R.id.view_stub);
navigation_view = (NavigationView) findViewById(R.id.navigation_view);
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout, 0, 0);
mDrawerLayout.setDrawerListener(mDrawerToggle);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
navigation_view.setNavigationItemSelectedListener(this);
navigation_view.setItemIconTintList(null);
navigation_view.setCheckedItem(R.id.home);
}
@Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
mDrawerToggle.syncState();
}
@Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
mDrawerToggle.onConfigurationChanged(newConfig);
}
@Override
public void setContentView(int layoutResID) {
if (mainView != null) {
LayoutInflater inflater = (LayoutInflater) getSystemService(LAYOUT_INFLATER_SERVICE);
ViewGroup.LayoutParams layoutParams = new ViewGroup.LayoutParams(
ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.MATCH_PARENT);
View stubView = inflater.inflate(layoutResID, mainView, false);
mainView.addView(stubView, layoutParams);
}
}
@Override
public void setContentView(View view) {
if (mainView != null) {
ViewGroup.LayoutParams layoutParams = new ViewGroup.LayoutParams(
ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.MATCH_PARENT);
mainView.addView(view, layoutParams);
}
}
@Override
public void setContentView(View view, ViewGroup.LayoutParams params) {
if (mainView != null) {
mainView.addView(view, params);
}
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if (mDrawerToggle.onOptionsItemSelected(item)) {
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {
return true;
}
}
MainActivity
public class MainActivity extends NavigationActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_about);
Toolbar toolbar=findViewById(R.id.my_toolbar);
setSupportActionBar(toolbar);
}
}
logs
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.toolbarimport/com.toolbarimport.Activity.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v7.app.ActionBar.setDisplayHomeAsUpEnabled(boolean)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3003)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3064)
at android.app.ActivityThread.-wrap14(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1659)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6816)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1565)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1453)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v7.app.ActionBar.setDisplayHomeAsUpEnabled(boolean)' on a null object reference
at com.toolbarimport.Activity.NavigationActivity.onCreate(NavigationActivity.java:38)
at com.toolbarimport.Activity.MainActivity.onCreate(MainActivity.java:12)
at android.app.Activity.performCreate(Activity.java:6977)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1126)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2946)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3064)
at android.app.ActivityThread.-wrap14(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1659)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6816)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1565)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1453)
