Question

Whenever the user clicks a button I want to get the selected row in a DataGrid and change its background color?
I can get the index of the selected row using the SelectedIndex property but I do not know how to change the background of the same.

I use WPF, C# and .Net 4 in VS2010.

Thanks…

Answer 1

It’s better to use triggers for this sort of things but try the following

private void button_Click(object sender, RoutedEventArgs e)
{
    DataGridRow dataGridRow = dataGrid.ItemContainerGenerator.ContainerFromIndex(dataGrid.SelectedIndex) as DataGridRow;
    if (dataGridRow != null)
    {
        dataGridRow.Background = Brushes.Green;
    }
}

Edit
The selected DataGridCells will still override that background so you would probably have to handle that as well, using the Tag property on the parent DataGridRow for example

<DataGrid ...>
    <DataGrid.CellStyle>
        <Style TargetType="DataGridCell">
            <Style.Triggers>
                <DataTrigger Binding="{Binding RelativeSource={RelativeSource AncestorType={x:Type DataGridRow}},
                                               Path=Tag}" Value="ChangedBackground">
                    <Setter Property="Background" Value="Transparent" />
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </DataGrid.CellStyle>
    <!--...-->
</DataGrid>

private void button_Click(object sender, RoutedEventArgs e)
{
    DataGridRow dataGridRow = dataGrid.ItemContainerGenerator.ContainerFromIndex(dataGrid.SelectedIndex) as DataGridRow;
    if (dataGridRow != null)
    {
        dataGridRow.Background = Brushes.Green;
        dataGridRow.Tag = "ChangedBackground";
    }
}