activity设置为全屏

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