C# - Populate A DropDownList Using A List <ListItem>?

I have a DropDownList.

I need populate it with item collected in a List<ListItem>.

In my script, collector has been populated properly.

But I cannot populate the DropDownList. I receive an error:

DataBinding: 'System.Web.UI.WebControls.ListItem' does not contain a property with the name 'UserName'."}

<asp:DropDownList ID="uxListUsers" runat="server" DataTextField="UserName"
DataValueField="UserId">
List<ListItem> myListUsersInRoles = new List<ListItem>();
foreach (aspnet_Users myUser in context.aspnet_Users)
{
// Use of navigation Property EntitySet
if (myUser.aspnet_Roles.Any(r => r.RoleName == "CMS-AUTHOR" || r.RoleName == "CMS-EDITOR"))
myListUsersInRoles.Add(new ListItem(myUser.UserName.ToString(), myUser.UserId.ToString()));
}
uxListUsers.DataSource = myListUsersInRoles; // MAYBE PROBLEM HERE????
uxListUsers.DataBind();