RadControls for ASP.NET AJAX In some particular scenarios you may want to allow single row expand at a time for each level in the grid hierarchy (due to user preference, custom development conventions, etc.). This feature is not built-in for Telerik RadGrid, however you can provide with only several lines of code. You merely need to:
Hook the ItemCommand event and check whether e.CommandName is RadGrid.ExpandCollapseCommandName
Traverse all items in the currently active GridTableView
Set the Expanded property for all items which differ from the e.Item instance to false
And here is the code of a simple demo:
CopyASPX
<telerik:RadGrid ID="RadGrid1" runat="server" AutoGenerateColumns="False">
<MasterTableView DataKeyNames="CustomerID" Width="100%">
<DetailTables>
<telerik:GridTableView DataKeyNames="OrderID" DataMember="Orders" Width="100%">
<ParentTableRelation>
<telerik:GridRelationFields DetailKeyField="CustomerID" MasterKeyField="CustomerID" />
</ParentTableRelation>
<DetailTables>
<telerik:GridTableView DataKeyNames="OrderID" DataMember="OrderDetails">
<ParentTableRelation>
<telerik:GridRelationFields DetailKeyField="OrderID" MasterKeyField="OrderID" />
</ParentTableRelation>
<Columns>
<telerik:GridBoundColumn SortExpression="UnitPrice" HeaderText="Unit Price" HeaderButtonType="TextButton"
DataField="UnitPrice">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn SortExpression="Quantity" HeaderText="Quantity" HeaderButtonType="TextButton"
DataField="Quantity">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn SortExpression="Discount" HeaderText="Discount" HeaderButtonType="TextButton"
DataField="Discount">
</telerik:GridBoundColumn>
</Columns>
</telerik:GridTableView>
</DetailTables>
<Columns>
<telerik:GridBoundColumn SortExpression="OrderID" HeaderText="OrderID" HeaderButtonType="TextButton"
DataField="OrderID">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn SortExpression="OrderDate" HeaderText="Date Ordered" HeaderButtonType="TextButton"
DataField="OrderDate">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn SortExpression="EmployeeID" HeaderText="EmployeeID" HeaderButtonType="TextButton"
DataField="EmployeeID">
</telerik:GridBoundColumn>
</Columns>
</telerik:GridTableView>
</DetailTables>
<Columns>
<telerik:GridBoundColumn SortExpression="CustomerID" HeaderText="CustomerID" HeaderButtonType="TextButton"
DataField="CustomerID">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn SortExpression="ContactName" HeaderText="Contact Name" HeaderButtonType="TextButton"
DataField="ContactName">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn SortExpression="CompanyName" HeaderText="Company" HeaderButtonType="TextButton"
DataField="CompanyName">
</telerik:GridBoundColumn>
</Columns>
</MasterTableView>
</telerik:RadGrid>CopyC#
private void RadGrid1_NeedDataSource(object source, Telerik.Web.UI.GridNeedDataSourceEventArgs e)
{
if (!e.IsFromDetailTable)
{
RadGrid1.DataSource = DataSourceHelperCS.GetDataTable("SELECT TOP 5 * FROM Customers");
}
RadGrid1.MasterTableView.DetailTables[0].DataSource = DataSourceHelperCS.GetDataTable("SELECT * FROM Orders");
RadGrid1.MasterTableView.DetailTables[0].DetailTables[0].DataSource = DataSourceHelperCS.GetDataTable("SELECT * FROM [Order Details]");
}
private void RadGrid1_ItemCommand(object source, Telerik.Web.UI.GridCommandEventArgs e)
{
if (e.CommandName == RadGrid.ExpandCollapseCommandName)
{
foreach (GridItem item in e.Item.OwnerTableView.Items)
{
if (item.Expanded && item != e.Item)
{
item.Expanded = false;
}
}
}
}CopyVB.NET
Private Sub RadGrid1_NeedDataSource(ByVal [source] As Object, ByVal e As Telerik.Web.UI.GridNeedDataSourceEventArgs) Handles RadGrid1.NeedDataSource
If Not e.IsFromDetailTable Then
RadGrid1.DataSource = DataSourceHelperCS.GetDataTable("SELECT TOP 5 * FROM Customers")
End If
RadGrid1.MasterTableView.DetailTables(0).DataSource = DataSourceHelperCS.GetDataTable("SELECT * FROM Orders")
RadGrid1.MasterTableView.DetailTables(0).DetailTables(0).DataSource = DataSourceHelperCS.GetDataTable("SELECT * FROM [Order Details]")
End Sub
Private Sub RadGrid1_ItemCommand(ByVal [source] As Object, ByVal e As Telerik.Web.UI.GridCommandEventArgs) Handles RadGrid1.ItemCommand
If e.CommandName = RadGrid.ExpandCollapseCommandName Then
Dim item As GridItem
For Each item In e.Item.OwnerTableView.Items
If item.Expanded AndAlso Not item Is e.Item Then
item.Expanded = False
End If
Next item
End If
End Sub