/// <summary>
 /// ConvertAll 将source中的每个元素转换为TResult类型
 /// </summary>
 public static IList <TResult> ConvertAll <TObject, TResult>(IEnumerable <TObject> source, Func <TObject, TResult> converter)
 {
     return(CollectionConverter.ConvertSpecification <TObject, TResult>(source, converter, null));
 }