RadControls for ASP.NET AJAX
You can retrieve the old values for the edited item through the
SavedOldValues property of the
GridEditableItem(which is
IDictionary collection of key -> value pairs). The keys in
this collection are the UniqueNames of the editable columns
and the values are the cell content for the edited row before the
edit operation.
The new values which the user entered before triggering the Update command can
be fetched calling the ExtractValuesFromItem
method.
Here is a sample code (note that this approach is applicable for
auto-generated grid column editors):
CopyASPX
<telerik:RadGrid ID="RadGrid1" DataSourceID="SqlDataSource1" AllowSorting="True"
runat="server" OnItemCommand="RadGrid1_ItemCommand" AutoGenerateColumns="true">
<MasterTableView DataSourceID="SqlDataSource1">
<Columns>
<telerik:GridEditCommandColumn UniqueName="EditCommandColumn">
</telerik:GridEditCommandColumn>
</Columns>
</MasterTableView>
</telerik:RadGrid>
<br />
<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString %>"
SelectCommand="SELECT TOP 10 [ContactName], [ContactTitle], [Address], [CustomerID] FROM [Customers]">
</asp:SqlDataSource>CopyC#
protected void RadGrid1_ItemCommand(object source, GridCommandEventArgs e)
{
if (e.CommandName == RadGrid.UpdateCommandName)
{
if (e.Item is GridEditableItem)
{
GridEditableItem editedItem = e.Item as GridEditableItem;
Hashtable newValues = new Hashtable();
e.Item.OwnerTableView.ExtractValuesFromItem(newValues, editedItem);
}
}
}CopyVB.NET
Protected Sub RadGrid1_ItemCommand(ByVal source As Object, ByVal e As GridCommandEventArgs)
If (e.CommandName = RadGrid.UpdateCommandName) Then
If (e.Item = GridEditableItem) Then
Dim editedItem As GridEditableItem = CType(e.Item, GridEditableItem)
Dim newValues As Hashtable = New Hashtable
e.Item.OwnerTableView.ExtractValuesFromItem(newValues, editedItem)
End If
End If
End Sub
If you have GridTemplateColumn inside the grid and want to
obtain its original values on update command, you will need to store the old
value on ItemDataBound when the grid item is in edit mode and
then reference it on update. The code snippet below uses a Session variable for
this purpose:
CopyASPX
<telerik:RadGrid ID="RadGrid1" DataSourceID="SqlDataSource1" Skin="WinXP" runat="server"
Width="150px">
<MasterTableView AutoGenerateColumns="false">
<Columns>
<telerik:GridTemplateColumn UniqueName="TemplateColumn" HeaderText="City">
<ItemTemplate>
<%# Eval("City") %>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="TextBox1" runat="server" Text='<%# Bind("City") %>' />
</EditItemTemplate>
</telerik:GridTemplateColumn>
<telerik:GridEditCommandColumn UniqueName="EditCommandColumn" />
</Columns>
</MasterTableView>
</telerik:RadGrid>
<br />
<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString"
SelectCommand="SELECTCity] FROMCustomers]">
</asp:SqlDataSource>CopyC#
protected void RadGrid1_UpdateCommand(object source,
Telerik.Web.UI.GridCommandEventArgs e)
{
RadGrid1.Controls.Add(new LiteralControl("Saved old value for the City editor is: " + (string)Session["savedOldValue"]));
}
protected void RadGrid1_ItemDataBound(object sender,
Telerik.Web.UI.GridItemEventArgs e)
{
if (e.Item isGridEditableItem && e.Item.IsInEditMode)
{
TextBox txtBox = e.Item.FindControl("TextBox1") as TextBox;
Session["savedOldValue"] = txtBox.Text;
}
}CopyVB.NET
Protected Sub RadGrid1_UpdateCommand(ByVal source As Object, ByVal e As Telerik.Web.UI.GridCommandEventArgs) Handles RadGrid1.UpdateCommand
RadGrid1.Controls.Add(New LiteralControl("Saved old value for the City editor is: " & CType(Session("savedOldValue"), String)))
End Sub
Protected Sub RadGrid1_ItemDataBound(ByVal sender As Object, ByVal e As Telerik.Web.UI.GridItemEventArgs) Handles RadGrid1.ItemDataBound
If (TypeOf e.Item Is GridEditableItem AndAlso e.Item.IsInEditMode) Then
Dim txtBox As TextBox = CType(e.Item.FindControl("TextBox1"), TextBox)
Session("savedOldValue") = txtBox.Text
End If
End Sub