Question

Is there a simple possibility to check if the DataGrid is currently in EditMode (Without to subscribe to BeginningEdit and CellEditEnding)

Answer 1

Ok, I havent found a simple solution and no one pointed me to one. The following code can be used to add an attached property IsInEditMode to a DataGrid. Hope it helps someone:

public class DataGridIsInEditModeTracker {

    public static bool GetIsInEditMode(DataGrid dataGrid) {
        return (bool)dataGrid.GetValue(IsInEditModeProperty);
    }

    private static void SetIsInEditMode(DataGrid dataGrid, bool value) {
        dataGrid.SetValue(IsInEditModePropertyKey, value);
    }

    private static readonly DependencyPropertyKey IsInEditModePropertyKey = DependencyProperty.RegisterAttachedReadOnly("IsInEditMode", typeof(bool), typeof(DataGridIsInEditModeTracker), new UIPropertyMetadata(false));

    public static readonly DependencyProperty IsInEditModeProperty = IsInEditModePropertyKey.DependencyProperty;


    public static bool GetProcessIsInEditMode(DataGrid dataGrid) {
        return (bool)dataGrid.GetValue(ProcessIsInEditModeProperty);
    }

    public static void SetProcessIsInEditMode(DataGrid dataGrid, bool value) {
        dataGrid.SetValue(ProcessIsInEditModeProperty, value);
    }


    public static readonly DependencyProperty ProcessIsInEditModeProperty =
        DependencyProperty.RegisterAttached("ProcessIsInEditMode", typeof(bool), typeof(DataGridIsInEditModeTracker), new FrameworkPropertyMetadata(false, delegate(DependencyObject d,DependencyPropertyChangedEventArgs e) {

            DataGrid dataGrid = d as DataGrid;
            if (null == dataGrid) {
                throw new InvalidOperationException("ProcessIsInEditMode can only be used with instances of the DataGrid-class");
            }
            if ((bool)e.NewValue) {
                dataGrid.BeginningEdit += new EventHandler<DataGridBeginningEditEventArgs>(dataGrid_BeginningEdit);
                dataGrid.CellEditEnding += new EventHandler<DataGridCellEditEndingEventArgs>(dataGrid_CellEditEnding);
            } else {
                dataGrid.BeginningEdit -= new EventHandler<DataGridBeginningEditEventArgs>(dataGrid_BeginningEdit);
                dataGrid.CellEditEnding -= new EventHandler<DataGridCellEditEndingEventArgs>(dataGrid_CellEditEnding);
            }
        }));

    static void dataGrid_CellEditEnding(object sender, DataGridCellEditEndingEventArgs e) {            
        SetIsInEditMode((DataGrid)sender,false);
    }

    static void dataGrid_BeginningEdit(object sender, DataGridBeginningEditEventArgs e) {
        SetIsInEditMode((DataGrid)sender, true);
    }                  
}

To use it, set on the datagrid the ProcessIsInEditMode- property to true:

<DataGrid local:DataGridIsInEditModeTracker.ProcessIsInEditMode="True" ..  other properties ..>

Afer that you will have the IsInEditMode-property in sync with the mode of the DataGrid.
If you want also the editing cell, change the code in BeginningEdit accoringly.