ReadOnly Mode for Individual Cells

Setting individual cells in read-only mode is not achievable in the current version of Telerik RadGrid.A possibleworkaround, however, is to disable the respective cell server-side to prevent the user from editing its content. This can be done by subscribing to the ItemCreated event of the grid:

ASP.NET

<telerik:RadGrid RenderMode="Lightweight" ID="RadGrid1" DataSourceID="SqlDataSource1" AllowSorting="True"
  runat="server" GridLines="None" Width="95%" AllowMultiRowEdit="True" HorizontalAlign="NotSet">
  <MasterTableView Width="100%" DataSourceID="SqlDataSource1" EditMode="InPlace"
    DataKeyNames="CustomerID">
    <Columns>
      <telerik:GridEditCommandColumn UniqueName="EditCommandColumn" />
    </Columns>
  </MasterTableView>
</telerik:RadGrid>
<br />
<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString %>"
    SelectCommand="SELECT * FROM [Customers]">
</asp:SqlDataSource>

VB

Protected Sub RadGrid1_ItemCreated(ByVal sender As Object, ByVal e As Telerik.Web.UI.GridItemEventArgs) Handles RadGrid1.ItemCreated
    'this will make the textbox for customer with CustomerID ALFKI not editable
    If (TypeOf e.Item Is GridEditableItem AndAlso e.Item.IsInEditMode) Then
        If (CType(e.Item.OwnerTableView.DataKeyValues(e.Item.ItemIndex)("CustomerID"), String) = "ALFKI") Then
            CType(e.Item, GridEditableItem)("CustomerID").Enabled = False
        End If
    End If
End Sub

C#

protected void RadGrid1_ItemCreated(object sender, Telerik.Web.UI.GridItemEventArgs e)
{
    // this will make the textbox for customer with CustomerID ALFKI not editable
    if (e.Item is GridEditableItem && e.Item.IsInEditMode)
    {
        if ((string)e.Item.OwnerTableView.DataKeyValues[e.Item.ItemIndex]["CustomerID"] == "ALFKI")
        {
            (e.Item as GridEditableItem)["CustomerID"].Enabled = false;
        }
    }
}