InvalidCastException: 不支持的格式转换，目标类型：Integer  源对象：System.String  ai1 ex:Parameter was not defined
Parameter name: ai1
StackTrace:
   at Quicker.Domain.Actions.X.Variables.VariableHelper.ConvertToType(VarType type, Object value)
   at Quicker.View.Forms.Controls.FormDropdownControl.GetInputValue()
   at Quicker.View.Forms.Controls.FormFieldWrapper.GetInputValue()
   at Quicker.View.Forms.FormWindow.OtZI3xbYZOp(Object  , FormField  )
   at Quicker.View.Forms.Controls.BaseFormFieldControl.TriggerValueChange(FormField field)
   at Quicker.View.Forms.Controls.FormFieldWrapper.FSKIo86vJP1(Object  , FormField  )
   at Quicker.View.Forms.Controls.BaseFormFieldControl.TriggerValueChange(FormField field)
   at Quicker.View.Forms.Controls.FormDropdownControl.CbValue_OnSelectionChanged(Object sender, SelectionChangedEventArgs e)
   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.Controls.ComboBox.OnSelectionChanged(SelectionChangedEventArgs e)
   at System.Windows.Controls.Primitives.Selector.SelectionChanger.End()
   at System.Windows.Controls.Primitives.Selector.SelectionChanger.SelectJustThisItem(ItemInfo info, Boolean assumeInItemsCollection)
   at System.Windows.Controls.ComboBox.NotifyComboBoxItemMouseUp(ComboBoxItem comboBoxItem)
   at System.Windows.Controls.ComboBoxItem.OnMouseLeftButtonUp(MouseButtonEventArgs e)
   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.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.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 System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)

ArgumentException: Parameter was not defined
Parameter name: ai1
--Message: Parameter was not defined
Parameter name: ai1
--ParamName: ai1
StackTrace:
   at NCalc.Domain.EvaluationVisitor.Visit(Identifier parameter)
   at NCalc.Expression.Evaluate()
   at Quicker.Domain.Actions.X.XActionHelper.EvaluateExpression(String expression)
   at Quicker.Domain.Actions.X.Variables.VariableHelper.qYkdtoyHspk(String  )
   at Quicker.Domain.Actions.X.Variables.VariableHelper.l5vdtNootTA(Object  )
   at Quicker.Domain.Actions.X.Variables.VariableHelper.ConvertToType(VarType type, Object value)