如何在没有RowDataBound的GridView ItemTemplate中找到DropDownList？

Question

I have a DropDownList outside of a GridView and I have a DropDownList inside an ItemTemplate of a GridView. The DropDownList that is outside has a SelectedIndex_Changed event and when that fires, it should populate the DropDownList inside the GridView. The problem is that in the method that I use to populate the inside DropDownList, it can't find the control: Here is sample code that is called when the outside DropDownList is changed:

 //Does not find ddlRoom
 DropDownList ddlRoom = (DropDownList)gv.TemplateControl.FindControl("ddlRoom");
    if (rows.Count() > 0)
    {

        var rooms = rows.CopyToDataTable();
        ddlRoom.Items.Clear();
        ddlRoom.Items.Add(new ListItem("Select...", "-1"));
        ddlRoom.DataSource = rooms;
        ddlRoom.DataBind();
    }

I have also tried:

DropDownList ddlRoom = (DropDownList)gv.FindControl("ddlRoom");

Answer 1

You'll need to bound the dropdown for each row. Try something like this

DropDownList ddlRoom = null;
foreach(var gridRow in gv.Rows)
{
    ddlRoom = gridRow.FindControl("ddlRoom") as DropDownList;
    if (ddlRoom != null)
    {
        //your code here
    }
}