线程中出现UnaughtException。IUncaughtExceptionHandler-未触发

我有一个非常简单的 Thread.IUncaughtExceptionHandler 如下所示

public class AirExceptionHandler : Java.Lang.Object, Thread.IUncaughtExceptionHandler
    {
        public static readonly string TAG = "AirExHandler";

        private MainActivity activity;
        private Thread.IUncaughtExceptionHandler defaultUEH;

        public AirExceptionHandler(MainActivity activity)
        {
            Log.Info(TAG, "Initialised");
            this.activity = activity;
            this.defaultUEH = Thread.DefaultUncaughtExceptionHandler;
        }

        public void SetActivity(MainActivity activity)
        {
            this.activity = activity;
        }
        public void UncaughtException(Thread t, Throwable e)
        {
            Log.Info(TAG, "Force Closed");
            JavaSystem.Exit(0);
        }
    }

在我的 Mainactivity ,我正在执行以下操作以初始化它 OnCreate

private static Handlers.AirExceptionHandler _unCaughtExceptionHandler;
.........
if (_unCaughtExceptionHandler == null)
   _unCaughtExceptionHandler = new Handlers.AirExceptionHandler(this);
else
   _unCaughtExceptionHandler.SetActivity(this);

if (Thread.DefaultUncaughtExceptionHandler != _unCaughtExceptionHandler)
    Thread.DefaultUncaughtExceptionHandler = (_unCaughtExceptionHandler);

我能看见 Log.Info(TAG, "Initialised"); 触发,但当我强制关闭我的应用程序时 UncaughtException 未触发

我做错了什么?