NotImplementedException: 未实现该方法或操作。
StackTrace:
   在 MS.Win32.UnsafeNativeMethods.ITfThreadMgr.CreateDocumentMgr(ITfDocumentMgr& docMgr)
   在 System.Windows.Input.TextServicesContext.RegisterTextStore(DefaultTextStore defaultTextStore)
   在 System.Windows.Input.DefaultTextStore.get_Current()
   在 System.Windows.Input.TextServicesContext.SetFocusOnDefaultTextStore()
   在 System.Windows.Input.InputMethod.EnableOrDisableInputMethod(Boolean bEnabled)
   在 System.Windows.Input.KeyboardDevice.ChangeFocus(DependencyObject focus, Int32 timestamp)
   在 System.Windows.Input.KeyboardDevice.TryChangeFocus(DependencyObject newFocus, IKeyboardInputProvider keyboardInputProvider, Boolean askOld, Boolean askNew, Boolean forceToNullIfFailed)
   在 System.Windows.Input.KeyboardDevice.Focus(DependencyObject focus, Boolean askOld, Boolean askNew, Boolean forceToNullIfFailed)
   在 System.Windows.Input.KeyboardDevice.Focus(IInputElement element)
   在 System.Windows.Interop.HwndKeyboardInputProvider.OnSetFocus(IntPtr hwnd)
   在 System.Windows.Interop.HwndKeyboardInputProvider.FilterMessage(IntPtr hwnd, WindowMessage message, IntPtr wParam, IntPtr lParam, Boolean& handled)
   在 System.Windows.Interop.HwndSource.InputFilterMessage(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 System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)