Modifying user control in WPF DataGrid on edit

Question

I am new to WPF and have hit a wall trying to solve a seemingly straightforward problem.

I need to design a table of data and allow users to edit it. When user starts editing a cell I need to display a set of buttons in the rightmost column [OK] and [Cancel] to either accept or cancel the changes. When user is not editing a cell a [Delete] button should be displayed for user to delete the row.

I wrote a custom control that would display either [OK][Cancel] or a single [Delete] button based on the custom IsInEditMode property.

public partial class RowEditControl : UserControl
{
    public static DependencyProperty
            IsInEditModeProperty = DependencyProperty.Register( "IsInEditMode", 
                                                                    typeof(bool), 
                                                                    typeof(RowEditControl),
                                                                    new FrameworkPropertyMetadata(OnEditModeChanged));

    private static void OnEditModeChanged(DependencyObject aD, DependencyPropertyChangedEventArgs aE)
    {
        //depending on the value show [Delete] or [Ok][Cancel] buttons
    }
}

I need to somehow set IsInEditMode when user starts editing a cell. I've been looking all over msdn and this forum for an example/way how to do it, but can't find anything.

I add my custom control to the last column programmatically like this:

        {
        mwTagList.Columns[1].Width = new DataGridLength(1, DataGridLengthUnitType.Star);

        var fRowEditTemplate = new FrameworkElementFactory(typeof (RowEditControl));

        fRowEditTemplate.AddHandler(
                                   RowEditControl.DeleteClickedEvent,
                                   new RoutedEventHandler(OnDeleteRowBtn)
            );

        fRowEditTemplate.AddHandler(
                                 RowEditControl.OkClickedEvent,
                                 new RoutedEventHandler(OnRowEditOk));

        fRowEditTemplate.AddHandler(
                                 RowEditControl.CancelClickedEvent,
                                 new RoutedEventHandler(OnRowEditCancel));

        mwTagList.Columns.Add(
                              new DataGridTemplateColumn()
                              {
                                  Header = "Delete Row",
                                  CellTemplate = new DataTemplate() {VisualTree = fRowEditTemplate}
                              }
            );
    }

Thank you very much for any info and tips!

Answer 1

I solved this problem using styles:

<Style x:Key="MwControlCellStyle" TargetType="{x:Type notesList:RowEditControl}">
        <Style.Triggers>
            <MultiDataTrigger>
                <MultiDataTrigger.Conditions>
                    <!-- find DataGridRow parent object and trigger if it is in editing mode -->
                    <Condition Binding="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type DataGridRow}}, Path=IsEditing}" Value="True"></Condition>
                </MultiDataTrigger.Conditions>
                <Setter Property="IsInEditMode" Value="True"></Setter>
            </MultiDataTrigger>
        </Style.Triggers>
    </Style>