C＃异步函数在第三次使用后退出线程

Question

我正在编写一个在Raspberry Pi和Windows IoT上运行的UWP应用程序的代码。

我有一个物理按钮（https://shkspr.mobi/blog/wp-content/uploads/2015/05/Push-Button-Pi.jpg） 和RFID阅读器（http://www.baaqii.com/promanage/productimage/Ewhole/A/A901-2.jpg）

每次按下按钮，我都希望应用程序显示弹出窗口。当我将RFID芯片放在RFID阅读器上时，它应该在其webview中显示某个HTML文件。

一切正常，但只能工作2次。在第三次RFID识别之后，我总是得到像这样的DebugMessage

The thread 0xb50 has exited with code 0 (0x0).
The thread 0xbd4 has exited with code 0 (0x0).
The thread 0x488 has exited with code 0 (0x0).
The thread 0x94c has exited with code 0 (0x0).
The thread 0x22c has exited with code 0 (0x0).
The thread 0x720 has exited with code 0 (0x0).

按钮和RFID阅读器不再工作了。我认为Dispatcher存在问题。

以下是四个功能：

private async void Button_ValueChanged(GpioPin sender, GpioPinValueChangedEventArgs e) {
                if (e.Edge == GpioPinEdge.RisingEdge) {
                    await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () => {
                        this.myHandler_ButtonPushed.Handle(new EventArgs());
                    });
                }
        }



private async void RFID_ValueChanged(GpioPin sender, GpioPinValueChangedEventArgs e) {
        if (e.Edge == GpioPinEdge.RisingEdge) {
            await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () => {
                this.myHandler_RfidIdentificated.Handle(new EventArgs());
            });
        }
    }


public void Button_pushed(EventArgs e) {
            popup1.IsOpen = true;
    }


public void Rfid_identificated(EventArgs e) {
     webview1.NavigateToLocalStreamUri(webview1.BuildLocalStreamUri("buttonURL", "/myDownloads/de-DE/47430155.html"), new Classes.StreamUriWinRTResolver());
     popup1.IsOpen = false;
    }