or

<%-- category--%> <telerik:GridTemplateColumn DataField="category" HeaderText="Category" SortExpression="category" UniqueName="category"> <EditItemTemplate> <telerik:RadDropDownList runat="server" ID="RadDropDownList3" DataTextField="category" AutoPostBack="true" DataValueField="category" DefaultMessage="Select Category" SelectedValue='<%#Bind("category") %>' OnSelectedIndexChanged="category_SelectedIndexChanged"> <Items> <telerik:DropDownListItem Text="India" Value='India' /> <telerik:DropDownListItem Text="International" Value='International' /> </Items> </telerik:RadDropDownList> <%-- <telerik:RadDropDownList ID="RadDropDownList6" runat="server"> </telerik:RadDropDownList>--%> </EditItemTemplate> <ItemTemplate> <asp:Label ID="lblcategory" runat="server" Text='<%# Bind("category")%>'></asp:Label> </ItemTemplate> </telerik:GridTemplateColumn> <%-- sub category--%> <telerik:GridTemplateColumn DataField="sub_category" HeaderText="Sub Category" SortExpression="sub_category" UniqueName="sub_category"> <EditItemTemplate> <telerik:RadDropDownList runat="server" ID="RadDropDownList5" DataTextField="sub_category" SelectedValue='<%#Bind("sub_category") %>' AutoPostBack="true" DataValueField="sub_category" DefaultMessage="Select Sub Category" RenderMode="Classic"> </telerik:RadDropDownList> <asp:HiddenField ID="hddlsubcategory" runat="server" Value='<%# Bind("sub_category") %>' /> </EditItemTemplate> <ItemTemplate> <asp:Label ID="Label5" runat="server" Text='<%# Bind("sub_category")%>'></asp:Label> </ItemTemplate> </telerik:GridTemplateColumn>and the code behind for this is:protected void category_SelectedIndexChanged(object sender, DropDownListEventArgs e) { RadDropDownList RadDropDownList3 = sender as RadDropDownList; GridEditFormItem item = RadDropDownList3.NamingContainer as GridEditFormItem; //Use GridDataItem when dropdown is in item template //GridDataItem item = RadDropDownList3.NamingContainer as GridDataItem; RadDropDownList ddlsubcategory = item.FindControl("RadDropDownList5") as RadDropDownList; if (RadDropDownList3.SelectedValue == "India") { //FillCat1(); ddlsubcategory.ClearSelection(); ddlsubcategory.Items.Add(new DropDownListItem("North", "North")); ddlsubcategory.Items.Add(new DropDownListItem("East", "East")); ddlsubcategory.Items.Add(new DropDownListItem("West", "West")); ddlsubcategory.Items.Add(new DropDownListItem("South", "South")); } else if (RadDropDownList3.SelectedValue == "International") { ddlsubcategory.ClearSelection(); ddlsubcategory.Items.Add(new DropDownListItem("Asia", "Asia")); ddlsubcategory.Items.Add(new DropDownListItem("Africa", "Africa")); ddlsubcategory.Items.Add(new DropDownListItem("Australia", "Australia")); ddlsubcategory.Items.Add(new DropDownListItem("America", "America")); } } protected void gvDetails_ItemDataBound(object sender, GridItemEventArgs e) { if (e.Item is GridEditFormItem && e.Item.IsInEditMode) { GridEditFormItem item = (GridEditFormItem)e.Item; //string value = item.GetDataKeyValue("ID").ToString(); RadDropDownList sub_category = item.FindControl("RadDropDownList5") as RadDropDownList; HiddenField hsubcategory = item.FindControl("hddlsubcategory") as HiddenField; if (sub_category != null && hsubcategory != null) { sub_category.SelectedValue = hsubcategory.Value; } } } 
