Data Grid for WPF - How to Process Related Cells in the Edit Form

This example illustrates how to process related cells in the Edit Form. This Edit Form contains information about goods. A user can change the Price value if the CanEdit checkbox is checked. PositionValue is the result of Price and Amount multiplication. Handle the RowEditStarting event to initialize values in editors when a user starts to edit the row. The CellValueChanging event handler disables the Price editor depending on the CanEdit value and calculates PositionValue.

void OnEditFormCellValueChanging(object sender, CellValueChangedEventArgs e) {
    CellValueChangedInEditFormEventArgs editFormArgs = e as CellValueChangedInEditFormEventArgs;
    //...
    if(e.Cell.Property == nameof(DataItem.CanEdit)) {
        var priceData = editFormArgs.CellEditors.FirstOrDefault(x => x.FieldName == nameof(DataItem.Price));
        priceData.ReadOnly = !bool.Parse(e.Cell.Value.ToString());
        return;     
    }
    if(e.Cell.Property == nameof(DataItem.Price)) {
        var positionValueData = editFormArgs.CellEditors.First(d => d.FieldName == nameof(DataItem.PositionValue));
        var amountData = editFormArgs.CellEditors.First(d => d.FieldName == nameof(DataItem.Amount));

         int price = 0;

         int.TryParse((string)e.Value, out price);
         positionValueData.Value = (int)amountData.Value * price;
    }
}

private void OnRowEditStarting(object sender, RowEditStartingEventArgs e) {
    var priceData = e.CellEditors.FirstOrDefault(x => x.FieldName == nameof(DataItem.Price));
    var canEditData = e.CellEditors.FirstOrDefault(x => x.FieldName == nameof(DataItem.CanEdit));
    priceData.ReadOnly = !(bool)canEditData.Value;
}

Alternatively, you can create commands in a View Model and bind them to the RowEditStartingCommand and CellValueChangingCommand properties.

In the TreeListView, use the following events and properties:

• NodeEditStarting
• TreeListView.CellValueChanging
• NodeEditStartingCommand
• TreeListView.CellValueChangingCommand

Files to Look At

Code-Behind

• MainViewModel.xaml.cs (MainViewModel.xaml.vb)
• MainWindow.xaml (MainWindow.xaml)

MVVM Pattern

• MainViewModel.cs (MainViewModel.vb)
• MainWindow.xaml (MainWindow.xaml)

Documentation

• Edit Form
• RowEditStarting / NodeEditStarting
• RowEditStartingCommand / NodeEditStartingCommand
• CellValueChanging / TreeListView.CellValueChanging
• CellValueChangingCommand / TreeListView.CellValueChangingCommand

More Examples

• Data Grid for WPF - How to Specify Edit Form Settings
• Data Grid for WPF - How to Pause Data Updates in the Edit Form

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