Android: show/hide status bar/power bar

I know its a very old question, but just in case anyone lands here looking for the newest supported way to hide status bar on the go programmatically, you can do it as follows:

window.insetsController?.hide(WindowInsets.Type.statusBars())

and to show it again:

window.insetsController?.show(WindowInsets.Type.statusBars())

For Some People, Showing status bar by clearing FLAG_FULLSCREEN may not work,

Here is the solution that worked for me, (Documentation) (Flag Reference)

Hide Status Bar

// Hide Status Bar
if (Build.VERSION.SDK_INT < 16) {
            getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                    WindowManager.LayoutParams.FLAG_FULLSCREEN);
}
else {
   View decorView = getWindow().getDecorView();
  // Hide Status Bar.
   int uiOptions = View.SYSTEM_UI_FLAG_FULLSCREEN;
   decorView.setSystemUiVisibility(uiOptions);
}

Show Status Bar

   if (Build.VERSION.SDK_INT < 16) {
              getWindow().clearFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
    }
    else {
       View decorView = getWindow().getDecorView();
      // Show Status Bar.
       int uiOptions = View.SYSTEM_UI_FLAG_VISIBLE;
       decorView.setSystemUiVisibility(uiOptions);
    }

Do you have the fullscreen theme set in the manifest?

android:theme="@android:style/Theme.NoTitleBar.Fullscreen"

I don't think you'll be able to go fullscreen without this.

I would use the following to add and remove the fullscreen flag:

// Hide status bar
getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
// Show status bar
getWindow().clearFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);

used for kolin in android for hide status bar in kolin no need to used semicolon(;) at the end of the line

window.addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN)

in android using java language for hid status bar

getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);