Android widget SearchView in onCreateOptionsMenu is null

Fill the entire canvas with the specified color.

@Override
    public void onDraw(Canvas canvas) {
    canvas.drawColor(Color.GREEN);
}

To hide a module File->Project Structure Ctrl+Alt+Shift+S
In left panel click on Module which want to hide.
Click on minus symbol (-) on upper left corner of window.
Click Yes.

To delete module from disk click on module in project tree (to select) and press Delete on keyboard.

Full Screen without titlebar and statusbar for Android Activity.
In Activity.java

public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
         requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
            WindowManager.LayoutParams.FLAG_FULLSCREEN);
        setContentView(R.layout.main);
    }

or in AndroidManifest.xml

<activity android:name=".ActivityName"
    android:label="@string/app_name"
    android:theme="@android:style/Theme.NoTitleBar.Fullscreen">
</activity>

Error: No Launcher activity found!
The launch will only sync the application package on the device!
Android emulator not showing the app
Workaround:
Check AndroidManifest.xml for MAIN and LAUNCHER. MyActivity.java is first Activity what will opened if .apk is installed.

<application android:label="@string/app_name" android:icon="@drawable/icon">
    <activity android:name="MyActivity"
              android:label="@string/app_name">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

if , else if, else statement with string as a switch statement in Java example source code.

MainClass.java

public class MainClass {
	public static void main(String[] arg) {
		String[] arrayOfString = {"nothing", "Hello", "people"
				, "bye-bye", "hello", "world!", "end" };
		for (int i = 0; i < arrayOfString.length; i++) {
			
			if (arrayOfString[i].equals("Hello"))
				System.out.println(arrayOfString[i]);
			else if (arrayOfString[i].equals("people"))
				System.out.println(arrayOfString[i]);
			else if (arrayOfString[i].equals("hello"))
				System.out.println(arrayOfString[i]);
			else if (arrayOfString[i].equals("world!"))
				System.out.println(arrayOfString[i]);
			else // default
				System.out.println("Default");
		}
	}
}
/*
Default
Hello
people
Default
hello
world!
Default 
 */