从Accelerometer.ReadingChanged调用NavigationService.Navigate会抛出NotSupportedException

Question

在下面,您可以看到我在发生震动事件时用来调用页面的代码.但是,页面弹出,但在同一时刻应用程序冻结,我无法进行任何进一步的用户输入,例如单击按钮.

void accelerometer_ReadingChanged(object sender, AccelerometerReadingEventArgs e)
{
    //double X, Y, Z;
    if (e.X > 1.5)
    {
        Dispatcher.BeginInvoke( () => { 
            NavigationService.Navigate(new Uri("/Bars/DetailBar.xaml", UriKind.Relative));
        } ); 
    } 
}

调试器告诉我,"NavigationFailed"并且存在"System.NotSupportedException".出了什么问题？

Answer 1

读数可能发生得太快,导致多次导航发生.尝试取消订阅活动:

void accelerometer_ReadingChanged(object sender, AccelerometerReadingEventArgs e)
{
    //double X, Y, Z;
    if (e.X > 1.5)
    {
        accelerometer.ReadingChanged -= accelerometer_ReadingChanged;

        Dispatcher.BeginInvoke( () => {    
            NavigationService.Navigate(new Uri("/Bars/DetailBar.xaml", UriKind.Relative));
        }); 

    } 
}