How to use the GridCalculatedColumn when there are no items in grid

[Venkatesh]

Hi,
I have added the "GridCalculatedColumn" in rad grid. where there are items in the grid, the calculated column is working fine. However when there are no items in grid, the gridcalculated column is giving the error as "operator * cannot be applied between string and string.".
Below is the code i have:

<telerik:GridTemplateColumn DataField="OrderQuantity" HeaderText="Order Quantity"
                    UniqueName="OrderQuantity" Visible="true">
                    <InsertItemTemplate>
                        <telerik:RadTextBox ID="RadtxtOrderQuantity" runat="server" Text="">
                        </telerik:RadTextBox>
                    </InsertItemTemplate>
                    <EditItemTemplate>
                        <telerik:RadTextBox ID="RadtxtOrderQuantity" runat="server" Text='<%# Eval("OrderQuantity") %>'>
                        </telerik:RadTextBox>
                    </EditItemTemplate>
                    <ItemTemplate>
                        <telerik:RadTextBox ID="RadtxtOrderQuantity" ReadOnly="true" runat="server" Text='<%# Eval("OrderQuantity") %>' />
                    </ItemTemplate>
                </telerik:GridTemplateColumn>

                <telerik:GridTemplateColumn DataField="UnitPrice" HeaderText="Unit Price" UniqueName="UnitPrice"
                    Visible="true">
                    <InsertItemTemplate>
                        <telerik:RadNumericTextBox ID="RadtxtUnitPrice" runat="server" >
                        </telerik:RadNumericTextBox>
                    </InsertItemTemplate>
                    <EditItemTemplate>
                        <telerik:RadNumericTextBox ID="RadtxtUnitPrice" runat="server" Text='<%# Eval("UnitPrice") %>'>
                        </telerik:RadNumericTextBox>
                    </EditItemTemplate>
                    <ItemTemplate>
                        <telerik:RadNumericTextBox ID="RadtxtUnitPrice" Type="Currency" ReadOnly="true" runat="server" Text='<%# Eval("UnitPrice") %>' />
                    </ItemTemplate>
                </telerik:GridTemplateColumn>



 <telerik:GridCalculatedColumn DataFormatString="{0:C}" DataType="System.Double" HeaderText="Extended Price"
                    UniqueName="ExtendedPrice" DataFields="OrderQuantity,UnitPrice" Expression="{0}*{1}"
                    FooterText="Total : " Aggregate="Sum">
                </telerik:GridCalculatedColumn>

How to modify the code to use when the grid has no items?
Thanks

[Tsvetoslav]

Hello Venkatesh,

I was not able to reproduce the issue described as evidenced by the attached sample. Please, take a look at it, modify it so that the problem is replicated and send it back to us for inspection. Thanks for that.

Greetings, Tsvetoslav
the Telerik team