Question

我TextBlock内有StackPanel。由于我正在使用TextTrimming，因此我必须根据TextBox手动设置StackPanel.ActualWidth的宽度。

<StackPanel HorizontalAlignment="Stretch">
    <TextBlock HorizontalAlignment="Left">
        <TextBlock.Width>
            <MultiBinding Converter="{StaticResource WidthConverter}">
                <MultiBinding.Bindings>
                    <Binding RelativeSource="{RelativeSource Self}" />
                    <Binding RelativeSource="{x:Static RelativeSource.Self}" Path="TemplatedParent.Parent.ActualWidth"  />
              </MultiBinding.Bindings>
             </MultiBinding>                
        </TextBlock.Width>
    </TextBlock>

我的转换器：

Public Class WidthConverter
    Implements IMultiValueConverter

    Public Function Convert(ByVal values() As Object, ByVal targetType As System.Type, ByVal parameter As Object, ByVal culture As System.Globalization.CultureInfo) As Object Implements System.Windows.Data.IMultiValueConverter.Convert

        Const TextBoxMarginRight As Double = 5

        Dim ParentWidth As Double = CType(CType(values(0), FrameworkElement).Parent, FrameworkElement).ActualWidth

        Dim ParentRelativeControlPosition As Point = CType(values(0), FrameworkElement).TransformToAncestor(CType(CType(values(0), FrameworkElement).Parent, Media.Visual)).Transform(New Point(0, 0))

        Dim Width As Double = ParentWidth - TextBoxMarginRight - ParentRelativeControlPosition.X

        If Width > 5 Then
            Return Width
        Else
            Return 0
        End If

    End Function

为什么这样做正常而不是下面的代码？（使用具有相同代码的IValueConverter）：

我的转换器可以获得StackPanel，但ActualWidth始终为零

<TextBlock.Width>

    <Binding RelativeSource="{x:Static RelativeSource.Self}" Path="TemplatedParent.Parent.ActualWidth"  Converter="{StaticResource WidthConverter}" />          
</TextBlock.Width>

Answer 1

尝试

Width="{Binding Path=ActualWidth, 
                RelativeSource={RelativeSource FindAncestor, AncestorType=StackPanel}}"

绑定与MultiBinding =＆gt;结果不同

1 个答案: