wpf 相对来源 FindAncestor 问题
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时间：2020-09-08 20:54:40 来源:igfitidea点击:
RelativeSource FindAncestor issue
提问by Teodor
Here is the code:
这是代码：
<GridViewColumn DisplayMemberBinding="{Binding Path=BookId}" Width="100">
<GridViewColumn.Header>
<Border BorderBrush="Black">
<TextBlock Width="{Binding RelativeSource=
{RelativeSource FindAncestor,
AncestorType={x:Type GridViewColumn}},
Path=Width}" Text="ID">
<TextBlock.ContextMenu>
<ContextMenu>item1</ContextMenu>
</TextBlock.ContextMenu>
</TextBlock>
</Border>
</GridViewColumn.Header>
</GridViewColumn>
Basically what i am trying to do is to make the TextBlock in the header follow the width of the whole column.
基本上我想要做的是使标题中的 TextBlock 跟随整列的宽度。
It is not working: the textblock's width always matches the text inside. Any ideas?... Thanks in advance!
它不起作用：文本块的宽度始终与里面的文本相匹配。有什么想法吗？...提前致谢！
回答by Thomas Levesque
There are two problems in your code
你的代码有两个问题
- the GridViewColumn is NOT a visual ancestor of the TextBox, its ancestor is a GridViewColumnHeader
- You should bind to the ActualWidth of the GridViewColumnHeader, not the Width (if Width is not specified, it will be an invalid number)
- GridViewColumn 不是 TextBox 的视觉祖先，它的祖先是 GridViewColumnHeader
- 您应该绑定到 GridViewColumnHeader 的 ActualWidth，而不是 Width（如果未指定 Width，它将是一个无效数字）
So your code becomes :
所以你的代码变成：
<GridViewColumn
DisplayMemberBinding="{Binding Path=BookId}"
Width="100">
<GridViewColumn.Header>
<Border BorderBrush="Black" >
<TextBlock Text="ID" Width="{Binding RelativeSource=
{RelativeSource FindAncestor,
AncestorType={x:Type GridViewColumnHeader}},
Path=ActualWidth}">
<TextBlock.ContextMenu>
<ContextMenu>item1</ContextMenu>
</TextBlock.ContextMenu>
</TextBlock>
</Border>
</GridViewColumn.Header>
</GridViewColumn>
