WPF DataGrid Column Width

I have a DataGrid in WPF with 3 columns. I would like these columns to take up all the space available in the grid. So for example:

Column 1 takes 40% of the grid's width Column 2 takes 30% of the grid's width Column 3 takes 30% of the grid's width

Such that even when resizing the window or grid the c开发者_如何学Columns width resizes accordingly. Anyway I can achieve this.

Thanks

Regards Gabriel.

I see you already found the answer you were looking for based on your comment. However, in case anybody else runs across this question trying to figure out how to get the column ratios (like your example of Column 1 = 40%, Column 2 = 30%, Column 3 = 30%), you can specify the ratios with * sizing for column widths as follows:

<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="4*" />
        <ColumnDefinition Width="3*" />
        <ColumnDefinition Width="3*" />
    </Grid.ColumnDefinitions>
</Grid>