Custom DropDownList control in ASP.NET 2.0

[Steve]

Hi

I've created a custom dropdown list in a web control library that my
aspx page uses as follows:

<%@ Register Assembly="CommonUI" Namespace="POLISY.Web.UI.Common"
TagPrefix="cc1" %>
....
<cc1:WFEDropDownList ID="WFEDropDownList1" runat="server">
<asp:ListItem Value="A">Apple</asp:ListItem>
<asp:ListItem Value="B">Banana</asp:ListItem>
</cc1:WFEDropDownList></td>

When I compile the .aspx I get the following error for each
<asp:ListItem> within a <cc1:WFEDropDownList> element:

Element 'ListItem' is not a known element. This can occur if there
is a compilation error in the Web site.

Any idea what's causing this? The code for WFEDropDownList is very
simple. All it does is extend DropDownList as follows:
using System.Web.UI;
using System.Web.UI.WebControls;
namespace POLISY.Web.UI.Common
{
[ToolboxData("<{0}:WFEDropDownList
runat=server></{0}:WFEDropDownList>")]
public class WFEDropDownList : DropDownList
{
// TO DO: Register javascript to display a tool tip for the
// currently selected item in the drop down. (needed in case
// of truncation)

}
}
Thanks for your help!

[DWS]

Steve,
You need to implement a collection in your WWE Dropdown list to hold the
list items. http://msdn2.microsoft.com/en-us/library/9txe1d4x.aspx

Too bad cause it seems like it would work automatically inheriting from
dropdownlist.

Good Luck
DWS
"Steve" wrote:

Hi

I've created a custom dropdown list in a web control library that my
aspx page uses as follows:

<%@ Register Assembly="CommonUI" Namespace="POLISY.Web.UI.Common"
TagPrefix="cc1" %>
....
<cc1:WFEDropDownList ID="WFEDropDownList1" runat="server">
<asp:ListItem Value="A">Apple</asp:ListItem>
<asp:ListItem Value="B">Banana</asp:ListItem>
</cc1:WFEDropDownList></td>

When I compile the .aspx I get the following error for each
<asp:ListItem> within a <cc1:WFEDropDownList> element:

Element 'ListItem' is not a known element. This can occur if there
is a compilation error in the Web site.

Any idea what's causing this? The code for WFEDropDownList is very
simple. All it does is extend DropDownList as follows:
using System.Web.UI;
using System.Web.UI.WebControls;
namespace POLISY.Web.UI.Common
{
[ToolboxData("<{0}:WFEDropDownList
runat=server></{0}:WFEDropDownList>")]
public class WFEDropDownList : DropDownList
{
// TO DO: Register javascript to display a tool tip for the
// currently selected item in the drop down. (needed in case
// of truncation)

}
}
Thanks for your help!