ArgumentNullException
   在 ICSharpCode.AvalonEdit.CodeCompletion.CompletionList.GetMatchQuality(String itemText, String query)
   在 ICSharpCode.AvalonEdit.CodeCompletion.CompletionList.<>c__DisplayClass35_0.<SelectItemFiltering>b__0(ICompletionData item)
   在 System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
   在 System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
   在 ICSharpCode.AvalonEdit.CodeCompletion.CompletionList.SelectItemFiltering(String query)
   在 ICSharpCode.AvalonEdit.CodeCompletion.CompletionList.SelectItem(String text)
   在 ICSharpCode.AvalonEdit.CodeCompletion.CompletionWindow.CaretPositionChanged(Object sender, EventArgs e)
   在 System.EventHandler.Invoke(Object sender, EventArgs e)
   在 ICSharpCode.AvalonEdit.Editing.Caret.OnDocumentUpdateFinished()
   在 ICSharpCode.AvalonEdit.Editing.TextArea.ReceiveWeakEvent(Type managerType, Object sender, EventArgs e)
   在 System.Windows.WeakEventManager.ListenerList.DeliverEvent(Listener& listener, Object sender, EventArgs args, Type managerType)
   在 System.Windows.WeakEventManager.ListenerList.DeliverEvent(Object sender, EventArgs args, Type managerType)
   在 System.Windows.WeakEventManager.DeliverEvent(Object sender, EventArgs args)
   在 ICSharpCode.AvalonEdit.Document.TextDocument.Replace(Int32 offset, Int32 length, ITextSource text, OffsetChangeMap offsetChangeMap)
   在 ICSharpCode.AvalonEdit.Editing.EmptySelection.ReplaceSelectionWithText(String newText)
   在 ICSharpCode.AvalonEdit.Editing.TextArea.PerformTextInput(TextCompositionEventArgs e)
   在 ICSharpCode.AvalonEdit.Editing.TextArea.OnTextInput(TextCompositionEventArgs e)
   在 System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
   在 System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
   在 System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
   在 System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
   在 System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args)
   在 System.Windows.Input.InputManager.ProcessStagingArea()
   在 System.Windows.Input.InputManager.ProcessInput(InputEventArgs input)
   在 System.Windows.Input.TextCompositionManager.PostProcessInput(Object sender, ProcessInputEventArgs e)
   在 System.Windows.Input.InputManager.RaiseProcessInputEventHandlers(ProcessInputEventHandler postProcessInput, ProcessInputEventArgs processInputEventArgs)
   在 System.Windows.Input.InputManager.ProcessStagingArea()
   在 System.Windows.Input.InputManager.ProcessInput(InputEventArgs input)
   在 System.Windows.Input.TextCompositionManager.PostProcessInput(Object sender, ProcessInputEventArgs e)
   在 System.Windows.Input.InputManager.RaiseProcessInputEventHandlers(ProcessInputEventHandler postProcessInput, ProcessInputEventArgs processInputEventArgs)
   在 System.Windows.Input.InputManager.ProcessStagingArea()
   在 System.Windows.Input.InputManager.ProcessInput(InputEventArgs input)
   在 System.Windows.Input.InputProviderSite.ReportInput(InputReport inputReport)
   在 System.Windows.Interop.HwndKeyboardInputProvider.ProcessTextInputAction(IntPtr hwnd, WindowMessage msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   在 System.Windows.Interop.HwndSource.OnPreprocessMessage(Object param)
   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)