Grid ignores ClipToBounds in WPF

Question

Given a really basic Grid, with ColumnDefinition's width set to *, the hardcoded width attribute of the button's contained within are ignored and these child elements are clipped. They are not clipped with a width set to Auto.

This clipping is prevented if correct MinWidths are set on each ColumnDefinition, but this is not exactly dynamic.

Am I doing things wrong or is this the best WPF has to offer?

becomes

Markup:

    <Grid ShowGridLines="True" ClipToBounds="False">
        <Grid.ColumnDefinitions>
            <ColumnDefinition></ColumnDefinition>
            <ColumnDefinition></ColumnDefinition>
            <ColumnDefinition></ColumnDefinition>
        </Grid.ColumnDefinitions>
            <Button Grid.Column="0" Width="120">AAAAA</Button>
            <Button Grid.Column="1" Width="120">BBBB</Button>
            <Button Grid.Column="2" Width="120">CCCCC</Button>
    </Grid>

I would like the buttons to appear as per the first image when there is room, and as image three when there is none (i.e. no clipping under any circumstances).

Answer 1

Ahh I've solved it as follows:

The key is the MinWidth attribute in the ColumnDefinition.

 <Grid ShowGridLines="True">
        <Grid.ColumnDefinitions>
            <ColumnDefinition MinWidth="{Binding Path=ActualWidth, ElementName=spLeft }"></ColumnDefinition>
            <ColumnDefinition MinWidth="{Binding Path=ActualWidth, ElementName=spMid }"></ColumnDefinition>
            <ColumnDefinition MinWidth="{Binding Path=ActualWidth, ElementName=spRight }"></ColumnDefinition>
        </Grid.ColumnDefinitions>
        <StackPanel Background="Red" Grid.Column="0" Name="spLeft" HorizontalAlignment="Center">
            <Button  Width="120">AAAAA</Button>
        </StackPanel>
        <StackPanel Background="Green" HorizontalAlignment="Center" Grid.Column="1" Name="spMid">
            <Button  Width="120">BBBB</Button>
        </StackPanel>
        <StackPanel Background="Blue" Name="spRight" Grid.Column="2" HorizontalAlignment="Center">
            <Button  Width="120">CCCCC</Button>
        </StackPanel>
    </Grid>