ASPxClientGridView.DetailRowExpanding Event

Fires before a detail row is expanded.

Declaration

DetailRowExpanding: ASPxClientEvent<ASPxClientGridViewRowCancelEventHandler<ASPxClientGridView>>

Event Data

The DetailRowExpanding event's data class is ASPxClientGridViewRowCancelEventArgs. The following properties provide information specific to this event:

Property	Description
cancel	Specifies whether to cancel the related action (for example, row edit, export). Inherited from ASPxClientCancelEventArgs.
visibleIndex	Gets the processed row’s visible index.

Remarks

Handle the DetailRowExpanding event to specify whether expandeding the detail row is allowed. The detail row currently being processed is identified by its visible index using the ASPxClientGridViewRowCancelEventArgs.visibleIndex property. To cancel this action, set the event parameter’s cancel property to true.

Example

By default, a master row is not focused when a user clicks the Expand Detail Row icon. To accomplish this task, handle the DetailRowExpanding event and focus a row using the SetFocusedRowIndex(visibleIndex) method.

Default.aspx (C#)

<script type="text/javascript">
    function OnDetailRowExpanding(s, e) {
        grid.SetFocusedRowIndex(e.visibleIndex);
    }
</script>
<dx:ASPxGridView ID="ASPxGridView1" runat="server" AutoGenerateColumns="False" DataSourceID="dsMain"
    ClientInstanceName="grid" KeyFieldName="CategoryID">
    <SettingsBehavior AllowFocusedRow="true" />
    <SettingsDetail ShowDetailRow="True" AllowOnlyOneMasterRowExpanded="true" />
    <ClientSideEvents DetailRowExpanding="OnDetailRowExpanding" />
    <Columns>
        <dx:GridViewDataTextColumn FieldName="CategoryID" ReadOnly="True" VisibleIndex="0">
            <EditFormSettings Visible="False" />
        </dx:GridViewDataTextColumn>
        <dx:GridViewDataTextColumn FieldName="CategoryName" VisibleIndex="1">
        </dx:GridViewDataTextColumn>
        <dx:GridViewDataTextColumn FieldName="Description" VisibleIndex="2">
        </dx:GridViewDataTextColumn>
    </Columns>
    <Templates>
        <DetailRow>
            <dx:ASPxGridView ID="ASPxGridView2" runat="server" AutoGenerateColumns="False" DataSourceID="dsDetail"
                KeyFieldName="ProductID" OnBeforePerformDataSelect="ASPxGridView2_BeforePerformDataSelect">
                <Columns>
                    <dx:GridViewDataTextColumn FieldName="ProductID" ReadOnly="True" VisibleIndex="0">
                        <EditFormSettings Visible="False" />
                    </dx:GridViewDataTextColumn>
                    <dx:GridViewDataTextColumn FieldName="ProductName" VisibleIndex="1">
                    </dx:GridViewDataTextColumn>
                    <dx:GridViewDataTextColumn FieldName="SupplierID" VisibleIndex="2">
                    </dx:GridViewDataTextColumn>
                    <dx:GridViewDataTextColumn FieldName="CategoryID" VisibleIndex="3">
                    </dx:GridViewDataTextColumn>
                    <dx:GridViewDataTextColumn FieldName="QuantityPerUnit" VisibleIndex="4">
                    </dx:GridViewDataTextColumn>
                    <dx:GridViewDataTextColumn FieldName="UnitPrice" VisibleIndex="5">
                    </dx:GridViewDataTextColumn>
                </Columns>
            </dx:ASPxGridView>
        </DetailRow>
    </Templates>
</dx:ASPxGridView>
<asp:SqlDataSource ID="dsMain" runat="server" ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString %>"
    SelectCommand="SELECT [CategoryID], [CategoryName], [Description] FROM [Categories]">
</asp:SqlDataSource>
<asp:SqlDataSource ID="dsDetail" runat="server" ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString %>"
    SelectCommand="SELECT [ProductID], [ProductName], [SupplierID], [CategoryID], [QuantityPerUnit], [UnitPrice] FROM [Products] WHERE ([CategoryID] = @CategoryID)">
    <SelectParameters>
        <asp:SessionParameter Name="CategoryID" SessionField="CategoryID" Type="Int32" />
    </SelectParameters>
</asp:SqlDataSource>

Default.aspx.cs

using DevExpress.Web.ASPxGridView;

public partial class _Default : System.Web.UI.Page {
    protected void Page_Load(object sender, EventArgs e) {

    }
    protected void ASPxGridView2_BeforePerformDataSelect(object sender, EventArgs e) {
        Session["CategoryID"] = (sender as ASPxGridView).GetMasterRowKeyValue();
    }
}

Default.aspx.vb

Imports DevExpress.Web.ASPxGridView

Partial Public Class _Default
    Inherits System.Web.UI.Page
    Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)

    End Sub
    Protected Sub ASPxGridView2_BeforePerformDataSelect(ByVal sender As Object, ByVal e As EventArgs)
        Session("CategoryID") = (TryCast(sender, ASPxGridView)).GetMasterRowKeyValue()
    End Sub
End Class

Default.aspx (VB.NET)

<script type="text/javascript">
    function OnDetailRowExpanding(s, e) {
        grid.SetFocusedRowIndex(e.visibleIndex);
    }
</script>
<dx:ASPxGridView ID="ASPxGridView1" runat="server" AutoGenerateColumns="False" DataSourceID="dsMain"
    ClientInstanceName="grid" KeyFieldName="CategoryID">
    <SettingsBehavior AllowFocusedRow="true" />
    <SettingsDetail ShowDetailRow="True" AllowOnlyOneMasterRowExpanded="true" />
    <ClientSideEvents DetailRowExpanding="OnDetailRowExpanding" />
    <Columns>
        <dx:GridViewDataTextColumn FieldName="CategoryID" ReadOnly="True" VisibleIndex="0">
            <EditFormSettings Visible="False" />
        </dx:GridViewDataTextColumn>
        <dx:GridViewDataTextColumn FieldName="CategoryName" VisibleIndex="1">
        </dx:GridViewDataTextColumn>
        <dx:GridViewDataTextColumn FieldName="Description" VisibleIndex="2">
        </dx:GridViewDataTextColumn>
    </Columns>
    <Templates>
        <DetailRow>
            <dx:ASPxGridView ID="ASPxGridView2" runat="server" AutoGenerateColumns="False" DataSourceID="dsDetail"
                KeyFieldName="ProductID" OnBeforePerformDataSelect="ASPxGridView2_BeforePerformDataSelect">
                <Columns>
                    <dx:GridViewDataTextColumn FieldName="ProductID" ReadOnly="True" VisibleIndex="0">
                        <EditFormSettings Visible="False" />
                    </dx:GridViewDataTextColumn>
                    <dx:GridViewDataTextColumn FieldName="ProductName" VisibleIndex="1">
                    </dx:GridViewDataTextColumn>
                    <dx:GridViewDataTextColumn FieldName="SupplierID" VisibleIndex="2">
                    </dx:GridViewDataTextColumn>
                    <dx:GridViewDataTextColumn FieldName="CategoryID" VisibleIndex="3">
                    </dx:GridViewDataTextColumn>
                    <dx:GridViewDataTextColumn FieldName="QuantityPerUnit" VisibleIndex="4">
                    </dx:GridViewDataTextColumn>
                    <dx:GridViewDataTextColumn FieldName="UnitPrice" VisibleIndex="5">
                    </dx:GridViewDataTextColumn>
                </Columns>
            </dx:ASPxGridView>
        </DetailRow>
    </Templates>
</dx:ASPxGridView>
<asp:SqlDataSource ID="dsMain" runat="server" ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString %>"
    SelectCommand="SELECT [CategoryID], [CategoryName], [Description] FROM [Categories]">
</asp:SqlDataSource>
<asp:SqlDataSource ID="dsDetail" runat="server" ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString %>"
    SelectCommand="SELECT [ProductID], [ProductName], [SupplierID], [CategoryID], [QuantityPerUnit], [UnitPrice] FROM [Products] WHERE ([CategoryID] = @CategoryID)">
    <SelectParameters>
        <asp:SessionParameter Name="CategoryID" SessionField="CategoryID" Type="Int32" />
    </SelectParameters>
</asp:SqlDataSource>