Select Value from GridDropDownColumn

[Ryan]

I hope this is an easy question to answer.  I have a RadGrid with various bound columns, one of which is a GridDropDownColumn.  I'm binding the column declaritively to a SQLDataSource as follows:

GridDropDownColumn:

<telerik:RadGrid runat="server" ID="rgUserMapping" AutoGenerateColumns="false" AllowPaging="true" PageSize="20">
...
    <%-- MasterTableView Settings --%>
    <MasterTableView AllowSorting="true" Caption="" Summary="" AllowFilteringByColumn="true" ItemStyle-VerticalAlign="Top" DataKeyNames="UserMappingID" CommandItemDisplay="Bottom" EditMode="PopUp">
...
        <%-- Columns --%>
        <Columns>
...
            <telerik:GridDropDownColumn DataField="Component" HeaderText="Component" FilterControlWidth="50" AutoPostBackOnFilter="true" CurrentFilterFunction="Contains" DataSourceID="dsComponentDataSource" ListTextField="Title" ListValueField="ID" DropDownControlType="RadComboBox" />
...
        </Columns>
    </MasterTableView>
</telerik:RadGrid>

When the RadGrid loads, I get what looks like text in the place of the  GridDropDownColumn, and the text is what would be the first item in the bound dropdownlist.

I want the text to read the actual value that comes from the database.  How do I make that happen?

[Princy]

Hello Ryan,


In browser mode, GridDropDownColumn looks and behaves like a standard GridBoundColumn. When in edit mode it displays a drop-down control for each edited cell in the column. If you want to display the dropdown box in normal mode, then you need to use DropDownList inside GridTemplateColumn.
In order to display corresponding value for each item in DropDownColumn, you have to set the ListValueField property to the name of the field in the lookup table that supplies the value for the field specified by the DataField property. 
Sample code below,

Mark-Up:

<telerik:GridDropDownColumn DataField="EmployeeID" HeaderText="Component" FilterControlWidth="50"
AutoPostBackOnFilter="true" CurrentFilterFunction="Contains" DataSourceID="dsComponentDataSource"
ListTextField="FirstName" ListValueField="EmployeeID" DropDownControlType="RadComboBox" />

You can also refer the "GridDropDownColumn" section in the following documentation for more details on this.
Column types


Thanks,
Princy.

[Ryan]

Thank you for your response.  I've also tried the GridTemplateColumn approach, and am unable to achieve the desired result.  Please see my definition of the GridTemplate Column blow and let me know if something's off.

<telerik:GridTemplateColumn>
    <ItemTemplate>
        <telerik:RadComboBox runat="server" ID="ddlComponent" DataSourceID="dsComponentDataSource"  DataTextField="Title" DataValueField="ID" />
    </ItemTemplate>
</telerik:GridTemplateColumn>

I obviously need a way to determine what the selected index of the dropdownlist should be, but am unaware of a property that I can set to determine that.

[Princy]

Hello Ryan,

You can use the SelectedValue property of RadComboBox to achieve this.Here is the example:
MarkUp:


<telerik:GridTemplateColumn>
           <ItemTemplate>
                 <telerik:RadComboBox runat="server" ID="ddlComponent" DataSourceID="dsComponentDataSource" DataTextField="Title" DataValueField="ID"   SelectedValue='<%# Bind("ID") %>' />
            </ItemTemplate>
</telerik:GridTemplateColumn>

Thanks,
Princy.

[Ryan]

Thanks.  I've considered that before, but Visual Studio intellisense didn't permit SelectedValue in the RadComboBox.  After reading your post, I decided to enter it anyway, and I got the following error: "The 'SelectedValue' property cannot be set declaritively".

My column is defined as follows:

<telerik:GridTemplateColumn DataField="Component" HeaderText="Component" FilterControlWidth="50" AutoPostBackOnFilter="true" CurrentFilterFunction="Contains">
    <ItemTemplate>
        <telerik:RadComboBox runat="server" ID="ddlComponent" DataSourceID="dsComponentDataSource" DataTextField="Title" DataValueField="ID" SelectedValue="<%#Bind("ID")%>" />
    </ItemTemplate>
</telerik:GridTemplateColumn>

Any other suggestions?

[Ryan]

I figured it out.  I didn't even need to use a TemplateColumn.  See the code below:

Markup:

<telerik:GridDropDownColumn UniqueName="Component" DataField="Component" HeaderText="Component" FilterControlWidth="50" AutoPostBackOnFilter="true" CurrentFilterFunction="Contains" DataSourceID="dsComponentDataSource" ListTextField="Title" ListValueField="ID" DropDownControlType="RadComboBox" />

Code Behind:

Protected Sub rgUserMapping_ItemDataBound(ByVal sender As Object, ByVal e As Telerik.Web.UI.GridItemEventArgs) Handles rgUserMapping.ItemDataBound
    'If the item is a standard DataItem
    If (TypeOf e.Item Is GridDataItem) Then
        'Get the item
        Dim objDataItem As GridDataItem = DirectCast(e.Item, GridDataItem)
        'Assign the text to the proper component
        Dim ltrComponent As Literal = DirectCast(objDataItem("Component").Controls(0), Literal)
        ltrComponent.Text = objDataItem.DataItem("Component")
    End If
    'If the item is an EditFormItem and it is currently in edit mode
    If ((TypeOf e.Item Is GridEditFormItem) AndAlso (e.Item.IsInEditMode)) Then
        'Get the item
        Dim objEditedItem As GridEditFormItem = DirectCast(e.Item, GridEditFormItem)
        'Select the correct component in the drop down
        Dim ddlComponent As RadComboBox = DirectCast(objEditedItem("Component").Controls(0), RadComboBox)
        ddlComponent.SelectedIndex = ddlComponent.FindItemIndexByText(objEditedItem.DataItem("Component"))
    End If
End Sub

Thanks!