Category / Section
How to add a blank item to deselect the selected item from GridComboBoxColumn dropdown without modifying actual source in WPF DataGrid?
2 mins read
By default, WPF DataGrid(SfDataGrid) GridComboBoxColumn doesn’t have any direct support to add blank item without modifying the ItemsSource of the GridComboBoxColumn. However, you can add blank item to the dropdown by adding a ComboBoxItem to GridComboBoxColumn.ItemsSource.
<Window.Resources>
<CollectionViewSource x:Key="ComboBoxItems" Source="{Binding Countries}" />
</Window.Resources>
<Grid>
<syncfusion:SfDataGrid Name="dataGrid"
AutoGenerateColumns="False"
ItemsSource="{Binding Employees}">
<syncfusion:SfDataGrid.Columns>
<syncfusion:GridComboBoxColumn MappingName="Country">
<syncfusion:GridComboBoxColumn.ItemsSource>
<CompositeCollection>
<ComboBoxItem Content="Blank"/>
<CollectionContainer Collection="{Binding Source={StaticResource ComboBoxItems}}" />
</CompositeCollection>
</syncfusion:GridComboBoxColumn.ItemsSource>
</syncfusion:GridComboBoxColumn>
</syncfusion:SfDataGrid.Columns>
</syncfusion:SfDataGrid>
</Grid>
You can set the SelectedItem of the ComboBox to null when the blank item is selected by creating custom renderer for the GridComboBoxcolumn.
public MainWindow()
{
InitializeComponent();
this.dataGrid.CellRenderers["ComboBox"] = new CustomComboBoxCellRenderer();
}
public class CustomComboBoxCellRenderer : GridCellComboBoxRenderer
{
public override void OnInitializeEditElement(DataColumnBase dataColumn, ComboBox uiElement, object dataContext)
{
uiElement.SelectionChanged += ComboBox_SelectionChanged;
base.OnInitializeEditElement(dataColumn, uiElement, dataContext);
}
private void ComboBox_SelectionChanged(object sender, System.Windows.Controls.SelectionChangedEventArgs e)
{
if (e.AddedItems.Count == 1 && e.AddedItems[0] is ComboBoxItem && (e.AddedItems[0] as ComboBoxItem).Content.ToString() == "Blank")
(sender as ComboBox).SelectedItem = null;
}
}
Take a moment to peruse the documentation, where you can find about GridComboBoxColumn, with code examples.
Please refer this link to know about the essential features of Syncfusion WPF DataGrid.
You can download the example from GitHub
