WPF: 共享Grid宽度或高度的方法

<StackPanel Margin="15" Grid.IsSharedSizeScope="True">
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="Auto" SharedSizeGroup="A"/>
            <ColumnDefinition Width="*"/>
            <ColumnDefinition Width="Auto" SharedSizeGroup="B"/>
        </Grid.ColumnDefinitions>
 
        <TextBlock Grid.Column="0" Text="Col 1"/>
        <TextBox Grid.Column="1" />
        <TextBlock Grid.Column="2" Text="3rd column here"/>
    </Grid>
 
    <Separator Margin="0,20"/>
 
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="Auto" SharedSizeGroup="A"/>
            <ColumnDefinition />
            <ColumnDefinition SharedSizeGroup="B"/>
        </Grid.ColumnDefinitions>
 
        <TextBlock Grid.Column="0" Text="1"/>
        <TextBox Grid.Column="1"/>
    </Grid>
</StackPanel>