MacaronLover MacaronLover - 7 months ago 71
Java Question

Android Snackbar not appearing when I click Option Item

I'm trying to display a Snackbar whenever I click my option item but when I do that, my app crashes. Does anyone know what is wrong here and what can be done to resolve this issue?

enter image description here

java

public class MainActivity extends AppCompatActivity {
private static CoordinatorLayout coordinatorLayout;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();

if (id == R.id.action_settings) {
Snackbar.make(coordinatorLayout, "Single Line SnackBar Demo.", Snackbar.LENGTH_SHORT).show();
return true;
}

return super.onOptionsItemSelected(item);
}
}


Logcat

04-17 09:22:58.260 20108-20108/com.apptacularapps.snackbar E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.apptacularapps.snackbar, PID: 20108
java.lang.NullPointerException
at android.support.design.widget.Snackbar.<init>(Snackbar.java:183)
at android.support.design.widget.Snackbar.make(Snackbar.java:215)
at com.apptacularapps.snackbar.MainActivity.onOptionsItemSelected(MainActivity.java:49)
at android.app.Activity.onMenuItemSelected(Activity.java:2600)
at android.support.v4.app.FragmentActivity.onMenuItemSelected(FragmentActivity.java:404)
at android.support.v7.app.AppCompatActivity.onMenuItemSelected(AppCompatActivity.java:179)
at android.support.v7.view.WindowCallbackWrapper.onMenuItemSelected(WindowCallbackWrapper.java:100)
at android.support.v7.view.WindowCallbackWrapper.onMenuItemSelected(WindowCallbackWrapper.java:100)
at android.support.v7.app.ToolbarActionBar$2.onMenuItemClick(ToolbarActionBar.java:69)
at android.support.v7.widget.Toolbar$1.onMenuItemClick(Toolbar.java:169)
at android.support.v7.widget.ActionMenuView$MenuBuilderCallback.onMenuItemSelected(ActionMenuView.java:760)
at android.support.v7.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:811)
at android.support.v7.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:152)
at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:958)
at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:948)
at android.support.v7.view.menu.MenuPopupHelper.onItemClick(MenuPopupHelper.java:191)
at android.widget.AdapterView.performItemClick(AdapterView.java:299)
at android.widget.AbsListView.performItemClick(AbsListView.java:1113)
at android.widget.AbsListView$PerformClick.run(AbsListView.java:2911)
at android.widget.AbsListView$3.run(AbsListView.java:3645)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5001)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
at dalvik.system.NativeStart.main(Native Method)

Answer

You are not initializing your coordinator layout. Initialize it like :

coordinatorLayout = (CoordinatorLayout) findViewById(R.id.yourCoordinatorLayoutId);