解决Android spinner下拉时Activity全屏失效，通知栏弹出

Activity onCreate 加上一行

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

protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    int flags = View.SYSTEM_UI_FLAG_FULLSCREEN | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
            | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY;
    getWindow().getDecorView().setSystemUiVisibility(flags);
    getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
}