Android 11全屏显示

 @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        //去掉标题栏
        this.requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(ActivityLoginBinding.inflate(getLayoutInflater()).getRoot());

        //设置全屏
        WindowInsetsController controller = getWindow().getInsetsController();
        controller.hide(WindowInsets.Type.systemBars());
        int behavior3 = WindowInsetsController.BEHAVIOR_SHOW_TRANSIENT_BARS_BY_SWIPE;
        controller.setSystemBarsBehavior(behavior3);
    }

如果有编辑还是显示导航栏的解决方案（重写onWindowFocusChanged）：

/**
 * 全屏显示
 *
 * @param hasFocus
 */
@Override
public void onWindowFocusChanged(boolean hasFocus) {
    super.onWindowFocusChanged(hasFocus);
    if (hasFocus) {
        WindowInsetsController controller = getWindow().getInsetsController();
        // 隐藏状态栏  导航栏 同时隐藏状态栏和导航栏
        controller.hide(WindowInsets.Type.systemBars());

        // 向后模式
        int behavior1 = WindowInsetsController.BEHAVIOR_SHOW_BARS_BY_TOUCH;
        // 沉浸模式
        int behavior2 = WindowInsetsController.BEHAVIOR_SHOW_BARS_BY_SWIPE;
        // 粘性沉浸模式
        int behavior3 = WindowInsetsController.BEHAVIOR_SHOW_TRANSIENT_BARS_BY_SWIPE;
        controller.setSystemBarsBehavior(behavior3);
    }
}