Keep Dropdown items attributes during async. postback

If you add custom attributes to ListItems such as color etc. the attributes are lost when a partial postback occurs. The attributes are not kept in ViewState.

One solution is to re-apply the styles when a partial postback occurs:

if (Page.IsPostBack)

{
     
if (ScriptManager.GetCurrent(this.Page).IsInAsyncPostBack)
     {
         foreach (ListItem Item in Drp_Tasks.Items)
         {
             if (Item.Value.Contains("WSS Task"))
                 Item.Attributes.Add("Style", "color:blue");
             else if (Item.Value.Contains("Timesheet Task"))
                 Item.Attributes.Add("Style", "color:green");
         }
     }
}

Another solution is to create a new ListItem class that keeps the attributes in ViewState.