WPF: DataGrid.RowDetailsTemplate: Only show details if single row is selected?

Question

I'm using the RowDetailsTemplate in one of my DataGrids. This works fine so far, but looks really odd when the user wants to select multiple rows for specific operations. Is there a simple way to display the RowDetailsTemplate only if exactly only one row is selected?

I'd love to solve this with pure XAML. Otherwise I'd do it with code behind:

private void DataGrid_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
    DataGrid temp = sender as DataGrid;

    if (temp.SelectedItems.Count == 1)
    {
        temp.RowDetailsVisibilityMode = DataGridRowDetailsVisibilityMode.VisibleWhenSelected;
    }
    else
    {
        temp.RowDetailsVisibilityMode = DataGridRowDetailsVisibilityMode.Collapsed;
    }
}

enapi · Accepted Answer · 2014-05-26T12:46:49.680

DataGrid has a property RowDetailsVisibilityMode. Set it to Collapsed when more than one row is selected. Your XAML should look something like

<DataGrid Name="dataGrid1" RowDetailsVisibilityMode="{Binding Path=SelectedItems.Count, RelativeSource={RelativeSource Self}, Converter={StaticResource rdtvc}}">

and the corresponding converter like

public class Converter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {

        if (value != null && (int)value == 1)
            return DataGridRowDetailsVisibilityMode.VisibleWhenSelected;
        else 
            return DataGridRowDetailsVisibilityMode.Collapsed;
    }

    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

...and what would be the best way to do that? I'd love to do that in XAML, but I cannot think of a proper way to do that... — Ralf, May 26 '14 at 12:25

score 2 · Answer 2 · answered Jul 10 '18 at 08:02

Based on the answer by user1994514 I developed a XAML-only version without the need for a converter. In case someone wants to avoid the additional converter you can use a style with a data trigger to achieve the same effect.

    <DataGrid>
        <DataGrid.Style>
            <Style TargetType="DataGrid">
                <Setter Property="RowDetailsVisibilityMode" Value="Collapsed" />
                <Style.Triggers>
                    <DataTrigger Binding="{Binding SelectedItems.Count, RelativeSource={RelativeSource Self}}" Value="1">
                        <Setter Property="RowDetailsVisibilityMode" Value="VisibleWhenSelected" />
                    </DataTrigger>
                </Style.Triggers>
            </Style>
        </DataGrid.Style>
    </DataGrid>

WPF: DataGrid.RowDetailsTemplate: Only show details if single row is selected?

2 Answers2