动态添加DataTemplate - 无法找到Converter的StaticResource

时间：2009-07-16 21:21:16

标签： wpf xaml dynamic datatemplate

我正在使用以下代码动态地向GridView添加列：

public void AddGridViewColumns()
{
    GridView view = (GridView)_myListView.View;
    GridViewColumn column = BuildGridViewColumn(1);
    view.Columns.Add(column);
}

public virtual GridViewColumn BuildGridViewColumn(int blockIndex)
{
    string templateXaml = string.Format(
        @"<DataTemplate
            xmlns=""http://schemas.microsoft.com/winfx/2006/xaml/presentation""
            xmlns:x=""http://schemas.microsoft.com/winfx/2006/xaml""
            xmlns:local=""clr-namespace:Pse.MyTest;assembly=MyTest"">
            <DataTemplate.Resources>
                <local:BlockToBrushConverter
                    x:Key=""_blockToBrushConverter"" />
            </DataTemplate.Resources>
            <TextBlock
                Style=""{{StaticResource _gridViewCenterItemStyle}}""
                Text=""{{Binding Path=Block{0}.ConditionLabel}}""
                Foreground=""{{Binding Path=Block{0}, Converter={{StaticResource _blockToBrushConverter}}}}"" />
        </DataTemplate>",
        blockIndex);
    System.Diagnostics.Debug.Print(templateXaml);
    GridViewColumn column = new GridViewColumn();
    column.Header = string.Format("Block {0}", blockIndex);
    column.CellTemplate = (DataTemplate)XamlReader.Parse(templateXaml);
    return column;
}

Debug.Print导致：

<DataTemplate
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="clr-namespace:Pse.MyTest;assembly=MyTest">
    <DataTemplate.Resources>
        <local:BlockToBrushConverter
            x:Key="_blockToBrushConverter" />
    </DataTemplate.Resources>
    <TextBlock
        Style="{StaticResource _gridViewCenterItemStyle}"
        Text="{Binding Path=Block1.ConditionLabel}"
        Foreground="{Binding Path=Block1, Converter={StaticResource _blockToBrushConverter}}" />
</DataTemplate>

当我运行它时，它说它无法找到_blockToBrushConverter。

例外是：

System.Windows.Markup.XamlParseException was unhandled
  Message="Cannot find resource named '{_blockToBrushConverter}'. Resource names are case sensitive.  Error at object 'System.Windows.Data.Binding' in markup file 'MyTest;component/SetupWindowDictionary.xaml' Line 23 Position 13."
  Source="PresentationFramework"
  LineNumber=23
  LinePosition=13
  NameContext="Foreground"

如果我删除Forecolor属性，XAML解析就好了（我得到了预期的结果）。似乎在DateTemplate.Resources中包含转换器应该保证它会被找到，但由于某种原因它不是。

我也尝试在树中将转换器资源的声明移到更高的位置（到Window级别），但这也无效。它似乎能够找到“_gridViewCenterItemStyle”，但由于某种原因，它拒绝找到转换器。

任何想法都非常感激。

以下是堆栈跟踪的完整异常，以防它有用：

System.Windows.Markup.XamlParseException was unhandled
  Message="Cannot find resource named '{_blockToBrushConverter}'. Resource names are case sensitive.  Error at object 'System.Windows.Data.Binding' in markup file 'MyTest;component/SetupWindowDictionary.xaml' Line 23 Position 13."
  Source="PresentationFramework"
  LineNumber=23
  LinePosition=13
  NameContext="Foreground"
  StackTrace:
       at System.Windows.Markup.XamlParseException.ThrowException(String message, Exception innerException, Int32 lineNumber, Int32 linePosition, Uri baseUri, XamlObjectIds currentXamlObjectIds, XamlObjectIds contextXamlObjectIds, Type objectType)
       at System.Windows.Markup.XamlParseException.ThrowException(ParserContext parserContext, Int32 lineNumber, Int32 linePosition, String message, Exception innerException)
       at System.Windows.Markup.BamlRecordReader.ThrowExceptionWithLine(String message, Exception innerException)
       at System.Windows.Markup.BamlRecordReader.ThrowException(String id, String parameter)
       at System.Windows.StaticResourceExtension.ProvideValueInternal(IBamlReader bamlReader, Object targetObject, Object targetProperty, Boolean allowDeferredReference)
       at System.Windows.StaticResourceExtension.ProvideValue(IServiceProvider serviceProvider)
       at System.Windows.Markup.BamlRecordReader.ProvideValueFromMarkupExtension(MarkupExtension markupExtension, Object obj, Object member)
       at System.Windows.Markup.BamlRecordReader.BaseReadOptimizedMarkupExtension(Object element, Int16 attributeId, PropertyDefinition propertyDefinition, Object value)
       at System.Windows.Markup.BamlRecordReader.ReadPropertyWithStaticResourceIdRecord(BamlPropertyWithStaticResourceIdRecord bamlPropertyWithStaticResourceIdRecord)
       at System.Windows.Markup.BamlRecordReader.ReadRecord(BamlRecord bamlRecord)
       at System.Windows.StyleHelper.LoadOptimizedTemplateContent(DependencyObject container, ParserContext parserContext, OptimizedTemplateContent optimizedTemplateContent, FrameworkTemplate frameworkTemplate, IComponentConnector componentConnector, IStyleConnector styleConnector, List`1 affectedChildren, UncommonField`1 templatedNonFeChildrenField)
       at System.Windows.FrameworkTemplate.LoadContent(DependencyObject container, List`1 affectedChildren, UncommonField`1 templatedNonFeChildrenField)
       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.GridViewRowPresenter.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.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.DockPanel.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)
       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.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.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.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.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Boolean isSingleParameter)
       at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
       at System.Windows.Threading.Dispatcher.WrappedInvoke(Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
       at System.Windows.Threading.DispatcherOperation.InvokeImpl()
       at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state)
       at System.Threading.ExecutionContext.runTryCode(Object userData)
       at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData)
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Windows.Threading.DispatcherOperation.Invoke()
       at System.Windows.Threading.Dispatcher.ProcessQueue()
       at System.Windows.Threading.Dispatcher.WndProcHook(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, Boolean isSingleParameter)
       at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
       at System.Windows.Threading.Dispatcher.WrappedInvoke(Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
       at System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Boolean isSingleParameter)
       at System.Windows.Threading.Dispatcher.Invoke(DispatcherPriority priority, Delegate method, Object arg)
       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 Pse.TestExperiment.App.Main() in C:\Documents and Settings\Daniel Manes\My Documents\Projects\Cmd21\Team Map Experiment 2\Solution\TestExperiment\obj\Debug\App.g.cs:line 0
       at System.AppDomain._nExecuteAssembly(Assembly 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)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException:

修改

问题解决了：我在整个项目中进行了搜索，并注意到我在我的一个资源字典中有一个额外的BlockToBrushConverter资源声明副本和相同的x：Key。一旦我消除了重复，问题就消失了。

1 个答案:

答案 0 :(得分：6)

以防万一有人在某一天看到这个问题，事实证明，我在这个问题的顶部提出的代码实际上是有效的。错误是我在XAML的其他地方有以下声明：

<local:BlockToBrushConverter
    x:Key="_blockToBrushConverter" />

我认为这种重复阻止了资源在动态DataTemplate的本地声明（它无法在同一个上下文中创建两次具有相同名称的资源）。

有一点对我来说尚未解决的是为什么有些StaticResources需要在本地声明，而其他的（如_gridViewCenterItemStyle StaticResource）可以在树中声明更高（例如在Window级别）而没有问题。< / p>

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