c# - WPF 祖先绑定(bind)

Question

出现此错误我做错了什么？

 xmlns:local="clr-namespace:TestSome.Views"

 <Button Grid.Row="0" Content="Button" Command="{Binding CloseInstanceCommand, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type local:CFDOpenPositionsView}}}" 
HorizontalAlignment="Left" Height="29.709" Margin="359.292,0,0,0" Style="{DynamicResource ButtonStyle4}" VerticalAlignment="Top" Width="66.728" Background="#FFDDDDDD" Visibility="Visible"/>

System.Windows.Data Error: 40 : BindingExpression path error: 'CloseInstanceCommand' property not found on 'object' ''CFDOpenPositionsView' (Name='')'. BindingExpression:
Path=CloseInstanceCommand; DataItem='CFDOpenPositionsView' (Name=''); target element is 'Button' (Name=''); target property is 'Command' (type 'ICommand')

CFDOpenPositionView 类具有 CloseInstanceCommand 属性...

Answer 1

RelativeSource 绑定(bind)将返回一个 UI 元素。您需要指定该属性位于 DataContext 对象上:

<Button Grid.Row="0" Content="Button" Command="{Binding DataContext.CloseInstanceCommand, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type local:CFDOpenPositionsView}}}"