wpf-devexpress-dot-xpf-dot-grid-dot-gridcontrol-30364296.md
Allows you to populate unbound columns with data.
Namespace : DevExpress.Xpf.Grid
Assembly : DevExpress.Xpf.Grid.v25.2.dll
NuGet Package : DevExpress.Wpf.Grid.Core
public event GridColumnDataEventHandler CustomUnboundColumnData
Public Event CustomUnboundColumnData As GridColumnDataEventHandler
The CustomUnboundColumnData event's data class is GridColumnDataEventArgs. The following properties provide information specific to this event:
| Property | Description |
|---|---|
| Column | Gets the unbound column currently being processed. |
| IsGetData | Gets whether you should provide data for the currently processed cell. Inherited from ColumnDataEventArgsBase. |
| IsSetData | Gets whether a cell’s value should be saved to a data source. Inherited from ColumnDataEventArgsBase. |
| ListSourceRowIndex | Gets the index of the record in a data source to which the processed row corresponds. |
| Source | Gets the grid control that raised the event. |
| Value | Gets or sets the processed cell’s value. Inherited from ColumnDataEventArgsBase. |
The event data class exposes the following methods:
| Method | Description |
|---|---|
| GetListSourceFieldValue(Int32, String) | Returns the value of the specified cell within the specified row in the grid’s data source. |
| GetListSourceFieldValue(String) | Returns the value of the specified cell within the processed row in the grid’s data source. |
Unbound Columns are not bound to any field in the data source. You can calculate unbound column values based on values of bound columns or populate unbound columns with data from a custom data source.
Handle the CustomUnboundColumnData event to populate unbound columns with data and save changes to a custom data source.
Display Unbound DataThe GridColumnDataEventArgs.IsGetData property returns true when the GridControl populates unbound columns with data. The GridColumnDataEventArgs.ListSourceRowIndex property returns the processed row’s index in a grid’s data source. Specify the GridColumnDataEventArgs.Value property to display data in the unbound column.Save ChangesThe GridColumnDataEventArgs.IsSetData property returns true when a user changes a cell value. The GridColumnDataEventArgs.Value property returns the modified cell value that you can save to a custom data source.
If you want to maintain a clean MVVM pattern and populate unbound columns with data in a View Model, create a command and bind it to the CustomUnboundColumnDataCommand property.
Note
The GridControl does not raise the CustomUnboundColumnData event if you use the TreeList View. Handle the TreeListView.CustomUnboundColumnData event instead.
This example shows how to add an unbound column to the GridControl. This column should display the total price, calculated as follows: UnitPrice * UnitsOnOrder.
View Example: How to Create Unbound Columns
<dxg:GridControl x:Name="grid"
CustomUnboundColumnData="grid_CustomUnboundColumnData">
<dxg:GridColumn FieldName="CompanyName"/>
<dxg:GridColumn FieldName="City"/>
<dxg:GridColumn FieldName="UnitPrice">
<dxg:GridColumn.EditSettings>
<dxe:TextEditSettings DisplayFormat="c2"/>
</dxg:GridColumn.EditSettings>
</dxg:GridColumn>
<dxg:GridColumn FieldName="Quantity"/>
<dxg:GridColumn FieldName="Total" UnboundDataType="{x:Type sys:Decimal}" ReadOnly="True">
<dxg:GridColumn.EditSettings>
<dxe:TextEditSettings DisplayFormat="c2"/>
</dxg:GridColumn.EditSettings>
</dxg:GridColumn>
<dxg:GridControl.View>
<dxg:TableView AutoWidth="True"/>
</dxg:GridControl.View>
</dxg:GridControl>
void grid_CustomUnboundColumnData(object sender, GridColumnDataEventArgs e) {
if(e.IsGetData) {
int price = Convert.ToInt32(e.GetListSourceFieldValue(nameof(Product.UnitPrice)));
int quantity = Convert.ToInt32(e.GetListSourceFieldValue(nameof(Product.Quantity)));
e.Value = price * quantity;
}
}
Private Sub grid_CustomUnboundColumnData(ByVal sender As Object, ByVal e As GridColumnDataEventArgs)
If e.IsGetData Then
Dim price As Integer = Convert.ToInt32(e.GetListSourceFieldValue(NameOf(Product.UnitPrice)))
Dim quantity As Integer = Convert.ToInt32(e.GetListSourceFieldValue(NameOf(Product.Quantity)))
e.Value = price * quantity
End If
End Sub
The following code snippets (auto-collected from DevExpress Examples) contain references to the CustomUnboundColumnData event.
Note
The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.
wpf-data-grid-create-unbound-columns/CS/DXGrid_UnboundColumns_CodeBehind/Window1.xaml#L9
<dxg:GridControl x:Name="grid"
CustomUnboundColumnData="grid_CustomUnboundColumnData">
<dxg:GridColumn FieldName="CompanyName"/>
<dxg:GridControl x:Name="grid"
CustomUnboundColumnData="GridControl_CustomUnboundColumnData">
<dxg:GridControl.Columns>
wpf-data-grid-change-background-color-for-modified-cells/CS/HighlightChangedCellBehavior.cs#L24
base.OnAttached();
AssociatedObject.CustomUnboundColumnData += OnGridCustomUnboundColumnData;
AssociatedObject.Loaded += OnGridLoaded;
wpf-data-grid-change-background-color-for-modified-cells/VB/HighlightChangedCellBehavior.vb#L40
MyBase.OnAttached()
AddHandler Me.AssociatedObject.CustomUnboundColumnData, AddressOf Me.OnGridCustomUnboundColumnData
AddHandler Me.AssociatedObject.Loaded, AddressOf Me.OnGridLoaded
See Also
TreeListView.CustomUnboundColumnData
How to Display an Icon in an Unbound Column Based on the Value in a Bound Column