c# - 在 WPF 应用程序中使用手写笔或手指按下触摸屏上的按钮时出现异常

Question

我有一个带有初始窗口的 WPF 应用程序，该窗口在启动时显示为 Splashscreen。在启动期间有一个后台线程，我们可以通过单击启动画面中的按钮来取消该线程。 使用鼠标并单击按钮取消时，一切正常。但是，如果我使用触摸屏单击此按钮，则应用程序偶尔会崩溃，以下是堆栈跟踪。该应用程序是在 Windows 7 64 位上运行的 64 位目标。

Severity:
Fatal


Stack Trace:
Exception 0
Message: Object reference not set to an instance of an object.

StackTrace:

at MS.Internal.PointUtil.TryClientToRoot(Point point, PresentationSource presentationSource, Boolean throwOnError, Boolean& success)
at System.Windows.Input.StylusDevice.GetPosition(IInputElement relativeTo)
at System.Windows.Input.StylusDevice.ChangeStylusOver(IInputElement stylusOver)
at System.Windows.Input.StylusLogic.PreProcessInput(Object sender, PreProcessInputEventArgs e)
at System.Windows.Input.InputManager.ProcessStagingArea()
at System.Windows.Input.InputProviderSite.ReportInput(InputReport inputReport)
at System.Windows.Interop.HwndMouseInputProvider.ReportInput(IntPtr hwnd, InputMode mode, Int32 timestamp, RawMouseActions actions, Int32 x, Int32 y, Int32 wheel)
at System.Windows.Interop.HwndMouseInputProvider.PossiblyDeactivate(IntPtr hwndCapture, Boolean stillActiveIfOverSelf)
at System.Windows.Interop.HwndMouseInputProvider.Dispose()
at System.Windows.Interop.HwndMouseInputProvider.FilterMessage(IntPtr hwnd, WindowMessage msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
at System.Windows.Interop.HwndSource.InputFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)
at System.Windows.Threading.Dispatcher.WrappedInvoke(Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
at System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)

FromSubsystem:
PresentationCore
Help Link:
Not specified

有没有人遇到过这个问题？

Answer 1

您使用的是 Elo 触摸屏吗？我在带有 Elo 触摸屏的 StylusLogic OnDispatcherShutdown 中遇到了类似的崩溃。我已经解决了它，为 wpf ( Disable the RealTimeStylus for WPF Applications ) 禁用了 RealTimeStylus。对我来说，事件被处理了两次(在显示驱动程序和 wpf stylus 中)，但是在 wpf Stylus 处理程序上，窗口已经被销毁了。在调用关闭窗口之前有一点延迟对我有用。