DataGrid ColumnWidth Property ignored in DataTemplate for row details

Question

This is the UserControl that displays the details from my application and as you can see the ColumnWidth Property is explicit set to *. I also tried to set the Width property from the DataGridTextColumn.

<UserControl x:Class="WpfUserInterface.MyDetailsView"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
         mc:Ignorable="d" Height="185" d:DesignWidth="480">
    <Grid>
        <DataGrid ColumnWidth="*" Margin="10">
            <DataGrid.Columns>
                <DataGridTextColumn Header="Column1"/>
                <DataGridTextColumn Header="Column2"/>
                <DataGridTextColumn Header="Column3"/>
            </DataGrid.Columns>
        </DataGrid>
    </Grid>
</UserControl>

This is the main window that only contains the DataGrid.

<Window x:Class="WpfUserInterface.Window"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Window" Height="306" Width="453">
    <Grid>
        <DataGrid ColumnWidth="*">
            <DataGrid.Columns>
                <DataGridTextColumn Header="ParentColumn1"/>
                <DataGridTextColumn Header="ParentColumn2"/>
                <DataGridTextColumn Header="ParentColumn3"/>
            </DataGrid.Columns>
            <DataGrid.RowDetailsTemplate>
                <DataTemplate>
                    <MyDetailsView/>
                </DataTemplate>
            </DataGrid.RowDetailsTemplate>
        </DataGrid>
    </Grid>
</Window>

This is what shows up on the screen when you run the application and select a row in the parent DataGrid.

When I set the width of the DataGrid in the MyDetailsView to a specified value like 400 the columns are sized perfect but this is not an option. Is there any way to solve this problem? A workaround?

Answer 1

I know this question was asked about a year ago, but I've been facing the same problem and I've found out this solution:

 this.dgrData.Columns[0].Width = new DataGridLength(1, DataGridLengthUnitType.Star);
 this.dgrData.Columns[1].Width = new DataGridLength(1, DataGridLengthUnitType.Star);
 ...

Hope it may be of any help to someone.