Binding a DropDownList inside a DetailsView

Question

I'm having problems trying to populate a dropdownlist from the database. When I'm trying to set the datasource I can't find the dropdown control, it's in a DetailsView so I think it might have something to do with it only being created when it's in edit mode. It still says it's in current mode when I'm editing though, so not sure what's going on there.

Here's the code from the aspx file:

<asp:DetailsView id="DetailsView1" runat="server" AutoGenerateRows="false" DataSourceID="myMySqlDataSrc"  DataKeyNames="id" AutoGenerateDeleteButton="True" AutoGenerateEditButton="True" AutoGenerateInsertButton="False" >
     <Fields>
        <asp:TemplateField HeaderText="Region">
            <ItemTemplate><%# Eval("region_name") %></ItemTemplate>
            <EditItemTemplate>
                <asp:DropDownList ID="RegionDropdownList" runat="server" SelectedValue='<%# Bind("region_id")%>' />
            </EditItemTemplate>
        </asp:TemplateField>        
     </Fields>
</asp:DetailsView>

And this is from the code behind:

ArrayList regionsList = BPBusiness.getRegions();
if (DetailsView1.CurrentMode == DetailsViewMode.Edit)
{
    DropDownList ddlRegions = (DropDownList)DetailsView1.FindControl("RegionDropdownList");
    if (ddlRegions != null)
    {
        ddlRegions.DataSource = regionsList;
        ddlRegions.DataBind();
    }
}

Answer 1

If it isn't already, place the sample from your code behind inside the DetailsView1_ModeChanged or DetailsView1_DataBound method. If it is in the DetailsView1_ModeChanging method, the mode has not actually changed yet.

EDIT: Also, make sure you set up the DataTextField and DataValueField like so:

DropDownList1.DataTextField = "TextFieldName";
DropDownList1.DataValueField = "ValueFieldName";

Also remove the SelectedValue bind; it does nothing except throw errors.

EDIT 2: If you really need to select a particular value of the dropdownlist when it first is databind, you could do something like this:

if(DropDownList1.Items.Contains(DropDownList1.Items.FindByValue("Value")))
{
    DropDownList1.SelectedIndex = DropDownList1.Items.IndexOf(DropDownList1.Items.FindByValue("Value));
}