ASPxGridView.CustomUnboundColumnData Event

Enables you to supply data to unbound columns.

Namespace: DevExpress.Web

Assembly: DevExpress.Web.v20.2.dll

NuGet Package: DevExpress.Web

Declaration

C#

public event ASPxGridViewColumnDataEventHandler CustomUnboundColumnData

VB.NET

Public Event CustomUnboundColumnData As ASPxGridViewColumnDataEventHandler

Event Data

The CustomUnboundColumnData event's data class is ASPxGridViewColumnDataEventArgs. 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 ASPxGridColumnDataEventArgs.
IsSetData	Gets whether the cell’s value should be stored in a custom data source. Inherited from ASPxGridColumnDataEventArgs.
ListSourceRowIndex	Gets the current data item’s (row, card or record) index in the data source. Inherited from ASPxGridColumnDataEventArgs.
Value	Gets or sets the value of the cell currently being processed. Inherited from ASPxGridColumnDataEventArgs.

The event data class exposes the following methods:

Method	Description
GetListSourceFieldValue(Int32, String)	Returns the value of the specified field in the specified data item (row, card or record) in the control’s underlying data source. Inherited from ASPxGridColumnDataEventArgs.
GetListSourceFieldValue(String)	Returns the value of the specified cell in the processed data item (row, card or record) in the control’s underlying data source. Inherited from ASPxGridColumnDataEventArgs.

Remarks

Note

The CustomUnboundColumnData event fires for unbound columns only.

Add a new data column to the ASPxGridView.Columns collection and set its GridViewDataColumn.UnboundType property to an appropriate value to create an unbound column. This column’s GridViewDataColumn.FieldName property value must be unique and it must not refer to any field in the ASPxGridView’s underlying data source.

When the ASPxGridView is loaded, it raises the CustomUnboundColumnData event for each cell in unbound columns. This allows you to populate cells with data. By default, the event’s ASPxGridColumnDataEventArgs.IsGetData parameter is set to true. In this case, you need to supply data for the currently processed cell. Obtain the required value from a custom data source and assign it to the ASPxGridColumnDataEventArgs.Value parameter.

The event’s ASPxGridColumnDataEventArgs.IsSetData parameter isn’t in effect. Handle the ASPxGridView.RowUpdating event to save the modified data back to the data source.

Use the ASPxGridViewColumnDataEventArgs.Column and ASPxGridColumnDataEventArgs.ListSourceRowIndex properties to identify a row and column to which the currently processed cell belongs.

The CustomUnboundColumnData event argument provides the ASPxGridColumnDataEventArgs.GetListSourceFieldValue method that allows you to get the required cell value.

Concept

Unbound Columns

Example

ASPX

<dx:ASPxGridView ID="Grid" ClientInstanceName="Grid" runat="server" AutoGenerateColumns="false"
        DataSourceID="ProductsDataSource" KeyFieldName="OrderID" OnInit="Grid_Init" OnCustomUnboundColumnData="Grid_CustomUnboundColumnData">
        <SettingsPager PageSize="5" />
        <Columns>
            <dx:GridViewDataTextColumn FieldName="ProductName" />
            <dx:GridViewDataSpinEditColumn FieldName="UnitPrice" >
                <PropertiesSpinEdit DisplayFormatString="c" DecimalPlaces="2" />
            </dx:GridViewDataSpinEditColumn>
            <dx:GridViewDataSpinEditColumn FieldName="Quantity" >
            </dx:GridViewDataSpinEditColumn>
            <dx:GridViewDataSpinEditColumn FieldName="Discount" >
                <PropertiesSpinEdit DisplayFormatString="p0"></PropertiesSpinEdit>
            </dx:GridViewDataSpinEditColumn>
        </Columns>
</dx:ASPxGridView>
<ef:EntityDataSource runat="server" ID="ProductsDataSource" ContextTypeName="DevExpress.Web.Demos.NorthwindContext" EntitySetName="Invoices" />

C#

using DevExpress.Web.ASPxGridView;

protected void Grid_Init(object sender, EventArgs e) {
    // Creates a column, customizes its settings and appends it to the Columns collection;
    GridViewDataTextColumn colTotal = new GridViewDataTextColumn();
    colTotal.FieldName = "Total";
    colTotal.UnboundType = DevExpress.Data.UnboundColumnType.Decimal;
    colTotal.VisibleIndex = Grid.VisibleColumns.Count;
    colTotal.PropertiesTextEdit.DisplayFormatString = "c2";
    Grid.Columns.Add(colTotal);
}
// Populates the unbound column.
protected void Grid_CustomUnboundColumnData(object sender,
    ASPxGridViewColumnDataEventArgs e) {
    if (e.Column.FieldName == "Total") {
        decimal unitPrice = Convert.ToDecimal(e.GetListSourceFieldValue("UnitPrice"));
        int quantity = Convert.ToInt32(e.GetListSourceFieldValue("Quantity"));
        decimal discount = Convert.ToDecimal(e.GetListSourceFieldValue("Discount"));
        e.Value = unitPrice * quantity * (1 - discount);
    }
}

VB.NET

Imports DevExpress.Web.ASPxGridView

Protected Sub Grid_Init(ByVal sender As Object, ByVal e As System.EventArgs)_
    Handles Grid.Init
    ' Creates a column, customizes its settings and appends it to the Columns collection;
    Dim colTotal As GridViewDataTextColumn = New GridViewDataTextColumn()
    colTotal.FieldName = "Total"
    colTotal.UnboundType = DevExpress.Data.UnboundColumnType.Decimal
    colTotal.VisibleIndex = Grid.VisibleColumns.Count
    colTotal.PropertiesTextEdit.DisplayFormatString = "c2"
    Grid.Columns.Add(colTotal)
End Sub

' Populates the unbound column.
Protected Sub Grid_CustomUnboundColumnData(ByVal sender As Object,_
   ByVal e As DevExpress.Web.ASPxGridViewColumnDataEventArgs)_
    Handles Grid.CustomUnboundColumnData
    If e.Column.FieldName = "Total" Then
        Dim unitPrice As Decimal = Convert.ToDecimal(e.GetListSourceFieldValue("UnitPrice"))
        Dim quantity As Integer = Convert.ToInt32(e.GetListSourceFieldValue("Quantity"))
        Dim discount As Decimal = Convert.ToDecimal(e.GetListSourceFieldValue("Discount"))
        e.Value = unitPrice * quantity * (1 - discount)
    End If
End Sub