TextBox.OnTextChanged 에서 발생하는 예외 처리

未处理 System.InvalidOperationException

  Message=无法关闭撤消单元，因为不存在已打开的单元。

  Source=PresentationFramework

  StackTrace:

       在 MS.Internal.Documents.UndoManager.Close(IParentUndoUnit unit, UndoCloseAction closeAction)

       在 System.Windows.Documents.ImmComposition.CloseCompositionUndoUnit(UndoCloseAction undoCloseAction, ITextPointer compositionEnd)

       在 System.Windows.Documents.ImmComposition.UpdateCompositionText(FrameworkTextComposition composition, Int32 resultLength, Boolean includeResultText, ITextPointer& start, ITextPointer& end)

       在 System.Windows.Documents.ImmComposition.RaiseTextInputStartEvent(FrameworkTextComposition composition, Int32 resultLength, String compositionString)

       在 System.Windows.Documents.ImmComposition.OnWmImeChar(IntPtr wParam, Boolean& handled)

       在 System.Windows.Documents.ImmComposition.ImmCompositionFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)

       在 System.Windows.Interop.HwndSource.PublicHooksFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)

       在 MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)

       在 MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)

       在 System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)

       在 MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)

       在 System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)

       在 MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)

       在 MS.Win32.UnsafeNativeMethods.CallWindowProc(IntPtr wndProc, IntPtr hWnd, Int32 msg, IntPtr wParam, IntPtr lParam)

       在 MS.Win32.HwndSubclass.DefWndProcWrapper(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)

       在 MS.Win32.UnsafeNativeMethods.CallWindowProc(IntPtr wndProc, IntPtr hWnd, Int32 msg, IntPtr wParam, IntPtr lParam)

       在 MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)

       在 MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)

       在 System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)

       在 System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)

       在 System.Windows.Application.RunDispatcher(Object ignore)

       在 System.Windows.Application.RunInternal(Window window)

       在 System.Windows.Application.Run(Window window)

       在 System.Windows.Application.Run()

       在 LiveChainCHIS_Client.App.Main() 位置 D:\项目\LiveChainCHIS-Client\LiveChainCHIS-Client\obj\x86\Debug\App.g.cs:行号 0

       在 System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)

       在 System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)

       在 Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()

       在 System.Threading.ThreadHelper.ThreadStart_Context(Object state)

       在 System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)

       在 System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)

       在 System.Threading.ThreadHelper.ThreadStart()

  InnerException: 

补充说明一下 ，这个错误只出现于 数据绑定后的TextBox控件上。

解决办法：  设置Textbox的UndoLimit 为0就ok。

중문 윈도우에서 중문 IME를 이용해 TextBox에 글자를 입력하려고 하면 발생하는 예외 처리 방법

위에 써있듯이 TextBox에 UndoLimit을 0으로 설정해주면 해결된다

출처 : http://www.cnblogs.com/muzizongheng/p/3169812.html