Linq实现下拉框绑定

         /// <summary>
        /// 绑定员工角色（系统角色）
        /// </summary>
        /// <param name="dropList">全部角色集合</param>
        /// <param name="roleType">角色类型 0  否  1 是 (系统角色)</param>
        public static void BindEmpRole(RadComboBox dropList, short roleType)
        {
            List<SysRole> roleList = SysRoleLogic.GetSysRoleOrCustomRole(1);

            if (roleType != -1)
            {
                var sysRoleList = from list in roleList where list.RoleType == roleType select list;

                dropList.DataSource = sysRoleList;                
            }
            else
            {
                dropList.DataSource = roleList;                
            }
            dropList.DataTextField = "RoleName";
            dropList.DataValueField = "RoleID";
            dropList.DataBind();            
        }