我正在使用WPF DataGrid，我放了一个DataGridTemplateColumn。因为列应该对复杂类型（它是一个对象）执行编辑，所以我决定放置一个打开弹出窗口的togglebutton。代码如下：
<DataTemplate>
<Grid>
<ToggleButton Grid.Column="2" x:Name="tb" Focusable="false" IsChecked="False" ClickMode="Press" Content="Edit values" />
<Popup IsOpen="{Binding ElementName=tb, Path=IsChecked, Mode=OneWay}" Placement="Bottom" x:Name="Popup" Focusable="False" StaysOpen="False" AllowsTransparency="True" Margin="0,1,0,0">
<Grid x:Name="dd" SnapsToDevicePixels="True">
<Border x:Name="ddb" Margin="0,-1,0,0" BorderBrush="DarkGray" BorderThickness="1" CornerRadius="0,0,3,3" Background="Gray">
<Grid>
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition />
<RowDefinition />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition />
<ColumnDefinition />
</Grid.ColumnDefinitions>
<TextBlock Text="Uno:" Grid.Row="0" Grid.Column="0" />
<TextBox Text="{Binding Path=calendar.uno, Mode=TwoWay, StringFormat={}{0:0.##}}" Grid.Row="0" Grid.Column="1" />
<TextBlock Text="Due:" Grid.Row="1" Grid.Column="0" />
<TextBox Text="{Binding Path=calendar.due, Mode=TwoWay, StringFormat={}{0:0.##}}" Grid.Row="1" Grid.Column="1" />
<TextBlock Text="Tre:" Grid.Row="2" Grid.Column="0" />
<TextBox Text="{Binding Path=calendar.tre, Mode=TwoWay, StringFormat={}{0:0.##}}" Grid.Row="2" Grid.Column="1" />
</Grid>
</Border>
</Grid>
</Popup>
</Grid>
</DataTemplate>
</DataGridTemplateColumn.CellEditingTemplate>
弹出窗口有效，但通常会发生以下异常：
System.ArgumentNullException was unhandled
Message=Value cannot be null.
Parameter name: descendant
Source=PresentationCore
ParamName=descendant
StackTrace:
at System.Windows.Media.VisualTreeHelper.IsAncestorOf(DependencyObject ancestor, DependencyObject descendant, Type stopType)
at System.Windows.Controls.DataGridCell.RemoveBindingExpressions(BindingGroup bindingGroup, DependencyObject element)
at System.Windows.Controls.DataGridCell.BuildVisualTree()
at System.Windows.Controls.DataGridCell.OnIsEditingChanged(Boolean isEditing)
at System.Windows.Controls.DataGridCell.OnIsEditingChanged(Object sender, DependencyPropertyChangedEventArgs e)
at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args)
at System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType)
at System.Windows.DependencyObject.SetValueCommon(DependencyProperty dp, Object value, PropertyMetadata metadata, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType, Boolean isInternal)
at System.Windows.DependencyObject.SetValue(DependencyProperty dp, Boolean value)
at System.Windows.Controls.DataGridCell.BeginEdit(RoutedEventArgs e)
at System.Windows.Controls.DataGrid.OnExecutedBeginEdit(ExecutedRoutedEventArgs e)
at System.Windows.Controls.DataGrid.OnExecutedBeginEdit(Object sender, ExecutedRoutedEventArgs e)
at System.Windows.Input.CommandBinding.OnExecuted(Object sender, ExecutedRoutedEventArgs e)
at System.Windows.Input.CommandManager.ExecuteCommandBinding(Object sender, ExecutedRoutedEventArgs e, CommandBinding commandBinding)
at System.Windows.Input.CommandManager.FindCommandBinding(CommandBindingCollection commandBindings, Object sender, RoutedEventArgs e, ICommand command, Boolean execute)
at System.Windows.Input.CommandManager.FindCommandBinding(Object sender, RoutedEventArgs e, ICommand command, Boolean execute)
at System.Windows.Input.CommandManager.OnExecuted(Object sender, ExecutedRoutedEventArgs e)
at System.Windows.UIElement.OnExecutedThunk(Object sender, ExecutedRoutedEventArgs e)
at System.Windows.Input.ExecutedRoutedEventArgs.InvokeEventHandler(Delegate genericHandler, Object target)
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.RaiseEvent(RoutedEventArgs args, Boolean trusted)
at System.Windows.Input.RoutedCommand.ExecuteImpl(Object parameter, IInputElement target, Boolean userInitiated)
at System.Windows.Input.RoutedCommand.Execute(Object parameter, IInputElement target)
at System.Windows.Controls.DataGrid.BeginEdit(RoutedEventArgs editingEventArgs)
at System.Windows.Controls.DataGridCell.OnAnyMouseLeftButtonDown(MouseButtonEventArgs e)
at System.Windows.Controls.DataGridCell.OnAnyMouseLeftButtonDownThunk(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.OnMouseDownThunk(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.InvokeImpl(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 WpfApplication5.App.Main() in C:\Users\r.sarati\Desktop\WpfDataGridSynchronized_V1.00\WpfDataGridSynchronized\CF40\WpfApplication5\obj\Debug\App.g.cs:line 50
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.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()
有什么问题？ （使用多列不是有效的替代方法）
答案 0 :(得分：1)
目前我的应用中也有这个例外;相同的堆栈跟踪。我发现这方面的解决方案也很少，但这些解决方案并不是很“好”：
1 我在整个对话框中使用了aero样式，我在其中使用DataGrid来查看不同Windows版本中的默认控件（主要用于XP以查看控件“更好”）。当我在对话框的xaml中发表以下部分代码时，没有显示其他异常：
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="/PresentationFramework.Aero, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, ProcessorArchitecture=MSIL;component/themes/aero.normalcolor.xaml" />
</ResourceDictionary.MergedDictionaries>
但我现在在XP上，我必须检查Win7上是否也解决了这个问题。 编辑：也适用于Windows7。
2 请尝试在微软页面上查看此链接：http://support.microsoft.com/kb/2498911
3 由于它也是在microsoft页面上编写的，你仍然可以关闭数据网格的行或列的虚拟化，但如果你有1000行，则需要一些时间来加载所有内容：/ < / p>
编辑：
4. 我下载了Aero.NormalColor.xaml（这里有一些主题来自microsoft：http://msdn.microsoft.com/en-us/library/aa970773.aspx）并将此主题添加到我的app.xaml到app词典中。这似乎解决了这个问题（可能看起来相同但在这个主题的代码中存在一些差异）。
<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="Themes/GlassButton.xaml"/>
<ResourceDictionary Source="Themes/Aero.NormalColor.xaml"/>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Application.Resources>