Question

我有WPF（.NET 4.5）客户端应用程序，其虚拟化ListBox中包含大量项目。每个ListBoxItem都有ContextMenu行动。

有些客户在打开ContextMenu时收到未处理的例外情况。几乎100％的人使用Windows 10和Windows Server 2012登录了一些PC。

System.Windows.Markup.XamlParseException消息：

设置属性'System.Windows.Controls.HeaderedContentControl.Header'抛出异常。 ---＆GT; System.InvalidOperationException：指定的元素已经是另一个元素的逻辑子元素。首先断开它。

注意：我尝试添加x:Shared="False" - 不是解决该问题

巨大异常StackTrace：

System.Windows.Markup.XamlParseException: Set property 'System.Windows.Controls.HeaderedContentControl.Header' threw an exception. ---> System.InvalidOperationException: Specified element is already the logical child of another element. Disconnect it first.
at System.Windows.FrameworkElement.ChangeLogicalParent(DependencyObject newParent)
at System.Windows.FrameworkElement.AddLogicalChild(Object child)
at System.Windows.Controls.HeaderedItemsControl.OnHeaderChanged(Object oldHeader, Object newHeader)
at System.Windows.Controls.HeaderedItemsControl.OnHeaderChanged(DependencyObject d, 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, Object value)
at System.Windows.Baml2006.WpfKnownMemberInvoker.SetValue(Object instance, Object value)
at MS.Internal.Xaml.Runtime.ClrObjectRuntime.SetValue(XamlMember member, Object obj, Object value)
at MS.Internal.Xaml.Runtime.ClrObjectRuntime.SetValue(Object inst, XamlMember property, Object value)
--- End of inner exception stack trace ---
at System.Windows.FrameworkTemplate.LoadTemplateXaml(XamlReader templateReader, XamlObjectWriter currentWriter)
at System.Windows.FrameworkTemplate.LoadTemplateXaml(XamlObjectWriter objectWriter)
at System.Windows.FrameworkTemplate.LoadOptimizedTemplateContent(DependencyObject container, IComponentConnector componentConnector, IStyleConnector styleConnector, List'1 affectedChildren, UncommonField'1 templatedNonFeChildrenField)
at System.Windows.FrameworkTemplate.LoadContent(DependencyObject container, List'1 affectedChildren)
at System.Windows.StyleHelper.ApplyTemplateContent(UncommonField'1 dataField, DependencyObject container, FrameworkElementFactory templateRoot, Int32 lastChildIndex, HybridDictionary childIndexFromChildID, FrameworkTemplate frameworkTemplate)
at System.Windows.FrameworkTemplate.ApplyTemplateContent(UncommonField'1 templateDataField, FrameworkElement container)
at System.Windows.FrameworkElement.ApplyTemplate()
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at System.Windows.Controls.Control.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at System.Windows.Controls.VirtualizingStackPanel.MeasureChild(IItemContainerGenerator& generator, IContainItemStorage& itemStorageProvider, IContainItemStorage& parentItemStorageProvider, Object& parentItem, Boolean& hasUniformOrAverageContainerSizeBeenSet, Double& computedUniformOrAverageContainerSize, Double& computedUniformOrAverageContainerPixelSize, Boolean& computedAreContainersUniformlySized, IList& items, Object& item, IList& children, Int32& childIndex, Boolean& visualOrderChanged, Boolean& isHorizontal, Size& childConstraint, Rect& viewport, VirtualizationCacheLength& cacheSize, VirtualizationCacheLengthUnit& cacheUnit, Boolean& foundFirstItemInViewport, Double& firstItemInViewportOffset, Size& stackPixelSize, Size& stackPixelSizeInViewport, Size& stackPixelSizeInCacheBeforeViewport, Size& stackPixelSizeInCacheAfterViewport, Size& stackLogicalSize, Size& stackLogicalSizeInViewport, Size& stackLogicalSizeInCacheBeforeViewport, Size& stackLogicalSizeInCacheAfterViewport, Boolean& mustDisableVirtualization, Boolean isBeforeFirstItem, Boolean isAfterFirstItem, Boolean isAfterLastItem, Boolean skipActualMeasure, Boolean skipGeneration, Boolean& hasBringIntoViewContainerBeenMeasured, Boolean& hasVirtualizingChildren)
at System.Windows.Controls.VirtualizingStackPanel.MeasureOverrideImpl(Size constraint, Nullable'1& lastPageSafeOffset, List'1& previouslyMeasuredOffsets, Nullable'1& lastPagePixelSize, Boolean remeasure)
at System.Windows.Controls.VirtualizingStackPanel.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at MS.Internal.Helper.MeasureElementWithSingleChild(UIElement element, Size constraint)
at System.Windows.Controls.ItemsPresenter.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at MS.Internal.Helper.MeasureElementWithSingleChild(UIElement element, Size constraint)
at System.Windows.Controls.ScrollContentPresenter.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at System.Windows.Controls.Grid.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at System.Windows.Controls.ScrollViewer.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at System.Windows.Controls.Control.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at System.Windows.Controls.Grid.MeasureCell(Int32 cell, Boolean forceInfinityV)
at System.Windows.Controls.Grid.MeasureCellsGroup(Int32 cellsHead, Size referenceSize, Boolean ignoreDesiredSizeU, Boolean forceInfinityV, Boolean& hasDesiredSizeUChanged)
at System.Windows.Controls.Grid.MeasureCellsGroup(Int32 cellsHead, Size referenceSize, Boolean ignoreDesiredSizeU, Boolean forceInfinityV)
at System.Windows.Controls.Grid.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at System.Windows.Controls.Decorator.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at System.Windows.Controls.Grid.MeasureCell(Int32 cell, Boolean forceInfinityV)
at System.Windows.Controls.Grid.MeasureCellsGroup(Int32 cellsHead, Size referenceSize, Boolean ignoreDesiredSizeU, Boolean forceInfinityV, Boolean& hasDesiredSizeUChanged)
at System.Windows.Controls.Grid.MeasureCellsGroup(Int32 cellsHead, Size referenceSize, Boolean ignoreDesiredSizeU, Boolean forceInfinityV)
at System.Windows.Controls.Grid.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at System.Windows.Controls.Grid.MeasureCell(Int32 cell, Boolean forceInfinityV)
at System.Windows.Controls.Grid.MeasureCellsGroup(Int32 cellsHead, Size referenceSize, Boolean ignoreDesiredSizeU, Boolean forceInfinityV, Boolean& hasDesiredSizeUChanged)
at System.Windows.Controls.Grid.MeasureCellsGroup(Int32 cellsHead, Size referenceSize, Boolean ignoreDesiredSizeU, Boolean forceInfinityV)
at System.Windows.Controls.Grid.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at MS.Internal.Helper.MeasureElementWithSingleChild(UIElement element, Size constraint)
at System.Windows.Controls.ContentPresenter.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at System.Windows.Controls.Border.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at System.Windows.Controls.Control.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at System.Windows.Controls.Decorator.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at System.Windows.Controls.Grid.MeasureCell(Int32 cell, Boolean forceInfinityV)
at System.Windows.Controls.Grid.MeasureCellsGroup(Int32 cellsHead, Size referenceSize, Boolean ignoreDesiredSizeU, Boolean forceInfinityV, Boolean& hasDesiredSizeUChanged)
at System.Windows.Controls.Grid.MeasureCellsGroup(Int32 cellsHead, Size referenceSize, Boolean ignoreDesiredSizeU, Boolean forceInfinityV)
at System.Windows.Controls.Grid.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at System.Windows.Controls.Grid.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at MS.Internal.Helper.MeasureElementWithSingleChild(UIElement element, Size constraint)
at System.Windows.Controls.ContentPresenter.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at System.Windows.Controls.Grid.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at System.Windows.Window.MeasureOverrideHelper(Size constraint)
at System.Windows.Window.MeasureOverride(Size availableSize)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at System.Windows.ContextLayoutManager.UpdateLayout()
at System.Windows.ContextLayoutManager.UpdateLayoutCallback(Object arg)
at System.Windows.Media.MediaContext.InvokeOnRenderCallback.DoWork()
at System.Windows.Media.MediaContext.FireInvokeOnRenderCallbacks()
at System.Windows.Media.MediaContext.RenderMessageHandlerCore(Object resizedCompositionTarget)
at System.Windows.Media.MediaContext.RenderMessageHandler(Object resizedCompositionTarget)
at System.Windows.Media.MediaContext.Resize(ICompositionTarget resizedCompositionTarget)
at System.Windows.Interop.HwndTarget.OnResize()
at System.Windows.Interop.HwndTarget.HandleMessage(WindowMessage msg, IntPtr wparam, IntPtr lparam)
at System.Windows.Interop.HwndSource.HwndTargetFilterMessage(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)

--Inner Exception:
System.InvalidOperationException: Specified element is already the logical child of another element. Disconnect it first.
at System.Windows.FrameworkElement.ChangeLogicalParent(DependencyObject newParent)
at System.Windows.FrameworkElement.AddLogicalChild(Object child)
at System.Windows.Controls.HeaderedItemsControl.OnHeaderChanged(Object oldHeader, Object newHeader)
at System.Windows.Controls.HeaderedItemsControl.OnHeaderChanged(DependencyObject d, 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, Object value)
at System.Windows.Baml2006.WpfKnownMemberInvoker.SetValue(Object instance, Object value)
at MS.Internal.Xaml.Runtime.ClrObjectRuntime.SetValue(XamlMember member, Object obj, Object value)
at MS.Internal.Xaml.Runtime.ClrObjectRuntime.SetValue(Object inst, XamlMember property, Object value)

ContextMenu资源（在UserControl.Resources标记中）：

<ContextMenu x:Key="QuestionContextMenu">
    <MenuItem Command="{Binding AddChildCommand}"
              CommandParameter="{Binding Model}"
              Header="{StaticResource s_Question_Tooltip_AddChildAnswer}" />
    <MenuItem Command="{Binding RemoveCommand}"
              CommandParameter="{Binding Model}"
              Header="{StaticResource s_Remove}" />
</ContextMenu>

DataTemplate资源（在UserControl.Resources标记中）：

<DataTemplate x:Key="dt_Questions"
              DataType="secure:QuestionViewModel">
    <Grid x:Name="MainGrid"
          Width="{Binding ElementName=lvQuestions, Path=ActualWidth}"
          MinHeight="22"
          ContextMenu="{StaticResource QuestionContextMenu}"
          Margin="0 2 0 2">
        ...
    </Grid>
</DataTemplate>

Xaml中的

ListBox：

<ListBox x:Name="lvQuestions"
         Grid.Row="1"
         Grid.Column="0"
         Grid.ColumnSpan="2"
         Padding="0 2 0 20"
         Panel.ZIndex="{Binding QuestionsZindex}"
         ItemTemplate="{StaticResource dt_Questions}"
         ItemsSource="{Binding QuestionsView, Mode=OneWay}"
         SelectedItem="{Binding SelectedQuestionViewModel, Mode=TwoWay}"
         SelectionMode="Single"
         Style="{StaticResource LeftListBox}"
         VirtualizingStackPanel.IsVirtualizing="True"
         VirtualizingStackPanel.ScrollUnit="Pixel"
         VirtualizingStackPanel.VirtualizationMode="Recycling" />

ListBox样式与模板：

<ItemsPanelTemplate x:Key="VirtualizingItemsPanelTemplate">
    <VirtualizingStackPanel />
</ItemsPanelTemplate>
<Style x:Key="LeftListBox"
        TargetType="{x:Type ListBox}">
    <Setter Property="OverridesDefaultStyle" Value="True" />
    <Setter Property="Padding" Value="0" />
    <Setter Property="Background" Value="{x:Null}" />
    <Setter Property="ItemsPanel" Value="{StaticResource VirtualizingItemsPanelTemplate}" />
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type ListBox}">
                <ScrollViewer Background="{TemplateBinding Background}"
                                            CanContentScroll="True"
                                            Style="{StaticResource LeftScrollViewerStyle}">
                    <ItemsPresenter Margin="{TemplateBinding Padding}" />
                </ScrollViewer>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

ListBoxItem模板：

<Style TargetType="ListBoxItem">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="ListBoxItem">
                <ContentPresenter />
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

我的想法：我使用ContextMenu错误，或者.NET 4.5中的ScrollUnit="Pixel"出现问题。

PS：我花了很多时间来确定问题来源是ContextMenu。我试图以某种方式重新制作我的XAML标记以解决该问题......问题仍然出现。我不想禁用虚拟化或自己进行ContextMenu控制。我想找到解决该问题的方法。

Answer 1

找到答案：

异常来源不是ContextMenu，MenuItem Header roperty设置为StaticResource我的本地化值。此值资源为TextBlock，而非String。

是：

<TextBlock x:Key="s_Question_Tooltip_AddChildAnswer">
    Add answer to this question
<TextBlock>

修正：

<s:String x:Key="s_Question_Tooltip_AddChildAnswer">
    Add answer to this question
</s:String>

虚拟化ListBox ContextMenu XamlParseException

1 个答案: