Question

我目前有一个AppDomain.CurrentDomain.UnhandledException处理程序，当应用程序崩溃时，它会通过电子邮件向我发送堆栈跟踪。这在大多数情况下工作得很好，但是当我在MVVM光视图模型中得到异常时，堆栈跟踪可能相当神秘，并没有真正告诉我它们在哪里发生。有没有一种简单的方法可以将我的viewmodel包装在try catch语句中，然后我可以在异常中注入一些更有用的信息然后重新抛出它？

以下是堆栈跟踪的示例：

   at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor)
   at System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at System.Reflection.MethodBase.Invoke(Object obj, Object[] parameters)
   at GalaSoft.MvvmLight.Helpers.WeakAction.Execute() in d:\GalaSoft\mydotnet\MvvmLight\Source\GalaSoft.MvvmLight\GalaSoft.MvvmLight (NET35)\Helpers\WeakAction.cs:line 269
   at GalaSoft.MvvmLight.Command.RelayCommand.Execute(Object parameter) in d:\GalaSoft\mydotnet\MvvmLight\Source\GalaSoft.MvvmLight\GalaSoft.MvvmLight (NET35)\Command\RelayCommand.cs:line 167
   at MS.Internal.Commands.CommandHelpers.CriticalExecuteCommandSource(ICommandSource commandSource, Boolean userInitiated)
   at System.Windows.Controls.Primitives.ButtonBase.OnClick()
   at System.Windows.Controls.Button.OnClick()
   at System.Windows.Controls.Primitives.ButtonBase.OnMouseLeftButtonUp(MouseButtonEventArgs e)
   at System.Windows.UIElement.OnMouseLeftButtonUpThunk(Object sender, MouseButtonEventArgs e)
   at System.Windows.Input.MouseButtonEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
   at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
   at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
   at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
   at System.Windows.UIElement.ReRaiseEventAs(DependencyObject sender, RoutedEventArgs args, RoutedEvent newEvent)
   at System.Windows.UIElement.OnMouseUpThunk(Object sender, MouseButtonEventArgs e)
   at System.Windows.Input.MouseButtonEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
   at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
   at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
   at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
   at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
   at System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args)
   at System.Windows.UIElement.RaiseEvent(RoutedEventArgs args, Boolean trusted)
   at System.Windows.Input.InputManager.ProcessStagingArea()
   at System.Windows.Input.InputManager.ProcessInput(InputEventArgs input)
   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.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.LegacyInvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
   at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
   at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
   at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
   at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
   at System.Windows.Threading.Dispatcher.Run()
   at System.Windows.Application.RunDispatcher(Object ignore)
   at System.Windows.Application.RunInternal(Window window)
   at System.Windows.Application.Run(Window window)
   at System.Windows.Application.Run()
   at MyApplication.App.Main() in c:|my computer\my projectname\obj\x86\Debug\App.g.cs:line 0
   at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
   at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
   at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
   at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.ThreadHelper.ThreadStart()

这是由我的viewmodel中包含在NotImplementedException中的方法中的RelayCommand引起的，因此我可以将按钮绑定到它。我无法弄清楚是什么让我知道方法的名称或viewmodel的名称。

Answer 1

您应该在InnerException属性中获得更多信息。

如果我没有记错，你的主要例外是TargetInvocationException类型。你可以写一个小方法来解开这个：

public Exception Unwrap(TargetInvocationException root)
{
    if(root.InnerException == null)
        return root;
    var innerException = root.InnerException as TargetInvocationException;
    if(innerException == null)
        return root.InnerException;

    return Unwrap(innerException);
}

这种方法很有用，因为通常你有多个TargetInvocationException级别，其中有3或4个真正的例外情况。

Answer 2

如果您已经处理了AppDomain.CurrentDomain.UnhandledException事件，是否可以在该处理程序中添加您的信息？：

public void MainWindow_UnhandledException(object sender, UnhandledExceptionEventArgs e)
{
    Exception exception = (Exception)e.ExceptionObject;
    if (exception.TargetSite.Module.ToString() == "nameOfViewModelAssembly.dll")
    {
        if (exception.StackTrace.Contains(nameOfSomeViewModel))
        {
            throw new Exception("Problem in nameOfSomeViewModel", exception);
        }
        else if (exception.StackTrace.Contains(nameOfOtherViewModel))
        {
            throw new Exception("Problem in nameOfOtherViewModel", exception);
        }
    }
}

当然，如果您有很多视图模型，这可能会变得非常大，但我相信您可以找到一种更有效的方法来实现这一目标。

如何在try catch语句中包装MVVM Light ViewModel？

2 个答案: