Question

我正在尝试从单独的窗口使用RadDiagram命令。我的绑定不起作用，因为“无法找到与引用绑定的源'ElementName = Diagram'”。我的（简化）XAML看起来像这样：

<UserControl x:Class="Client.Wpf.EditableLayoutControl"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
             xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation"
             xmlns:s="clr-namespace:Client.Wpf" xmlns:Converters="clr-namespace:Client.Wpf.Converters"
             mc:Ignorable="d" DataContext="{Binding RelativeSource={RelativeSource Self}}"
             d:DesignHeight="300" d:DesignWidth="800" Background="Transparent" Name="Root">
    <UserControl.Resources>
        <Converters:MultiBoolToVisibilityConverter x:Key="multiBoolToVis"/>
        <Converters:ObjectToBooleanConverter x:Key="objToBool"/>
        <telerik:InvertedBooleanConverter x:Key="invBool"/>
    </UserControl.Resources>
    <telerik:RadDocking HasDocumentHost="False" BorderThickness="0" Name="DockingStation">
        <telerik:RadSplitContainer>
            <telerik:RadPaneGroup>
                <telerik:RadPane CanDockInDocumentHost="False" Title="Controls" >
                    <telerik:RadPane.TitleTemplate>
                        <DataTemplate>
                            <Grid Margin="0 5">
                                <ContentPresenter Content="{Binding}" VerticalAlignment="Center"/>
                                <telerik:RadButton Command="telerik:DiagramCommands.Undo" CommandTarget="{Binding Path=Diagram, Source={RelativeSource FindAncestor, AncestorType={x:Type s:EditableLayoutControl}}}" />
                            </Grid>
                        </DataTemplate>
                    </telerik:RadPane.TitleTemplate>
                    <telerik:RadTabControl ...></telerik:RadTabControl>
                </telerik:RadPane>
            </telerik:RadPaneGroup>
        </telerik:RadSplitContainer>
        <telerik:RadSplitContainer>
            <telerik:RadPaneGroup>
                <telerik:RadPane PaneHeaderVisibility="Collapsed" HorizontalAlignment="Stretch" HorizontalContentAlignment="Stretch">
                    <Grid>
                        <telerik:RadDiagram Name="Diagram">...
                        </telerik:RadDiagram>
                    </Grid>
                </telerik:RadPane>
            </telerik:RadPaneGroup>
        </telerik:RadSplitContainer>
    </telerik:RadDocking>
</UserControl>

有问题的代码行是来自DataTemplate的内容：

CommandTarget="{Binding Path=Diagram, Source={RelativeSource FindAncestor, AncestorType={x:Type s:EditableLayoutControl}}}"

这行代码不起作用，因为Diagram不是属性，绑定需要属性。使用ElementName而不是Path也不起作用，因为ElementName和Source是独占的。我也试过这个：

CommandTarget="{Binding ElementName=Diagram}"

这行代码不起作用。它给出了这个错误：

System.Windows.Data Error: 4 : Cannot find source for binding with reference 'ElementName=Diagram'. BindingExpression:(no path); DataItem=null; target element is 'RadButton' (Name=''); target property is 'CommandTarget' (type 'IInputElement')

我也试过了CommandTarget="{x:Reference Diagram}"，但是这个功能显然还没有在.NET 4.0中实现。怎么做？

Answer 1

在这种特殊情况下，我必须在撤消按钮上设置Loaded事件。然后在我的事件处理程序（代码隐藏）中我做了这个：((RadButton)e.Source).CommandTarget = Diagram;。

棘手的命令源问题

1 个答案: