public static string GetDisplayMemberMember(GridView obj)
 {
     return (string)obj.GetValue(DisplayMemberMemberProperty);
 }
 public static string GetHeaderTextMember(GridView obj)
 {
     return (string)obj.GetValue(HeaderTextMemberProperty);
 }
 public static object GetColumnsSource(GridView obj)
 {
     return obj.GetValue(ColumnsSourceProperty);
 }