Xamarin: Window返回空，如何获取Window？

Question

我正在尝试在Xamarin for Android中获取窗口，但窗口返回空。我想要获得窗口的原因是，我可以应用一个标志来删除UI状态栏。

我已经寻找了一个与getWindow(java)等效的方法，但是没有找到。在本例中，我尝试使用this.Window：

            var _winflag1 = WindowManagerFlags.Fullscreen;

            this.Window.AddFlags(_winflag1); // window is always null

这不起作用，所以我也尝试了实例化，但没有用：

            var _winflag1 = WindowManagerFlags.Fullscreen;

            var _window = this.Window; //_window is always null

            _window.AddFlags(_winflag1);

我想知道一种在Xamarin.Android中获取当前窗口的方法。

编辑:我忘记提到这是在MainActivity.cs内部。

https://github.com/hexag0d/BitChute_Mobile_Android_BottomNav/blob/FixLinkOverflow/MainActivity.cs

Answer 1

问题是窗口变量必须在MainActivity.cs OnCreate中赋值。

public class MainActivity : FragmentActivity
{
   //it is very important to instantiate with static
   public static Window _window = null; // do this directly inside MainActivity

    protected override void OnCreate(Bundle savedInstanceState)
    {

       //bunch of code here

      _window = this.Window; //we can only assign Window inside 
               //OnCreate??  I tried to do it in another custom method
                //but it would always return null
    }

    public void MyCustomWindowMethod()
    {
         //I was previously trying to assign window inside this method
         //that doesn't work.

         //this var hides the statusbar on android
         var _winflag1 = WindowManagerFlags.Fullscreen;

         //since we assigned window in OnCreate, now _window isn't null
         _window.AddFlags(_winflag1); 
    }
}