ComboBox within Grid issue...

[Richard]

I am unable to set the selectedvalue of a combobox with a templatecolumn edititemtemplate of a grid.

The values of the combobox are set in the onitemcreated event. The combo box has the  SelectedValue='<%# Eval("insurer") %>' statement... however this prevents the grid from going into edit mode.

here is the code:

 <telerik:RadGrid
            ID="RadGrid1"
            runat="server"
            AutoGenerateColumns="False"
            AutoGenerateDeleteColumn="True"
            AllowSorting="True"
            AutoGenerateEditColumn="True"
            ondeletecommand="RadGrid1_DeleteCommand"
            oninsertcommand="RadGrid1_InsertCommand"
            onupdatecommand="RadGrid1_UpdateCommand"
            onneeddatasource="RadGrid1_NeedDataSource"
            GridLines="None"
            OnItemCreated="RadGrid1_ItemCreated"  >
            <MasterTableView
                CommandItemDisplay="Top"
                CommandItemSettings-AddNewRecordImageUrl="../Images/AddRecord.gif"
                CommandItemSettings-RefreshImageUrl="../Images/Refresh.gif"
                EditMode="InPlace"
                DataKeyNames="contractor_id,insurer,tstamp">
                <CommandItemSettings
                    AddNewRecordImageUrl="../Images/AddRecord.gif"
                    RefreshImageUrl="../Images/Refresh.gif">
                </CommandItemSettings>
                <RowIndicatorColumn>
                    <HeaderStyle Width="20px"></HeaderStyle>
                </RowIndicatorColumn>
                <ExpandCollapseColumn>
                    <HeaderStyle Width="20px"></HeaderStyle>
                </ExpandCollapseColumn>
                <Columns>
                   
                    <telerik:GridTemplateColumn UniqueName="TemplateColumn1">
                     <HeaderTemplate>Insurer</HeaderTemplate>
                     <ItemTemplate>
                         <%# Eval("insurer") %>
                     </ItemTemplate>
                     <EditItemTemplate>
                        <qese:QeseComboBox
                            ID="comboRadGrid1Insurer"
                            runat="server"
                            SelectedValue='<%# Eval("insurer") %>'>
                         </qese:QeseComboBox>
                     </EditItemTemplate>
                    </telerik:GridTemplateColumn>
                    <telerik:GridBoundColumn
                        DataField="employer_id"
                        HeaderText="Employer ID"
                        UniqueName="column1">
                    </telerik:GridBoundColumn>
                    <telerik:GridBoundColumn
                        DataField="no_of_members"
                        HeaderText="No. of members"
                        UniqueName="column2">
                    </telerik:GridBoundColumn>
                </Columns>
            </MasterTableView>
            <HeaderStyle Font-Bold="False" Font-Italic="False" Font-Overline="False"
                Font-Size="XX-Small" Font-Strikeout="False" Font-Underline="False"
                Wrap="True" />
        </telerik:RadGrid>

    protected void RadGrid1_ItemCreated(object sender, GridItemEventArgs e)
    {
        if (e.Item is GridEditableItem)
        {
            QeseComboBox combo = (e.Item as GridEditableItem)["TemplateColumn1"].FindControl("comboRadGrid1Insurer") as QeseComboBox;
            if (combo != null)
            {
                combo.DataSource = Tbl_contractor_personal_accident_insurance.SelectDistinctInsurer();
                combo.DataTextField = "Value";
                combo.DataValueField = "Key";
                combo.DataBind();

            }
        }
    }

Any input would be appreciated?

[Shinu]

Hi Richard,

Bind the SelectedValue property for the ComboBox as shown below.

ASPX:

<EditItemTemplate>
    <qese:QeseComboBox
         ID="comboRadGrid1Insurer"
         runat="server"
         SelectedValue='<%# Bind("insurer")%>' >
    </qese:QeseComboBox>
   </EditItemTemplate>

You can also refer the following help article.
Known reasons for error messages

Thanks
Shinu.

[Richard]

Thanks Shinu,

That works, however only if you do not bind the datasource in the itemcreated event, conversely it must done so in the objectdatasource.

Otherwise you get an error when it tries to set SelectedValue='<%# Bind("insurer")%>'...

"Databinding methods such as Eval(), XPath(), and Bind() can only be used in the context of a databound control."

Looks like a timing issue, ie the # Bind is called before there is any data bound to the control.

[Yavor]

Hi Richard,

The same behavior will hold true for a standard dropdown control as well. If you set the selected value for the control, do not bind it dynamically, and alternatively, if you bind it dynamically, in the code-behind, do not set the selected value. This will ensure the consistent behavior of the control.

Regards,
Yavor
the Telerik team

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