c#延迟加载
public class BlogUser { public int Id { get; private set; } public Lazy<List<Article>> Articles { get; private set; } public BlogUser(int id) { this.Id = id; Articles = new Lazy<List<Article>>(() => ArticleServices.GetArticesByID(id)); Console.WriteLine("BlogUser Initializer"); } } public class Article { public int Id { get; set; } public string Title { get; set; } public DateTime PublishDate { get; set; } } public class ArticleServices { public static List<Article> GetArticesByID(int blogUserID) { List<Article> articles = new List<Article> { new Article{Id=1,Title="Lazy Load",PublishDate=DateTime.Parse("2011-4-20")}, new Article{Id=2,Title="Delegate",PublishDate=DateTime.Parse("2011-4-21")}, new Article{Id=3,Title="Event",PublishDate=DateTime.Parse("2011-4-22")}, new Article{Id=4,Title="Thread",PublishDate=DateTime.Parse("2011-4-23")} }; Console.WriteLine("Article Initalizer"); return articles; } }
main
BlogUser blogUser = new BlogUser(1); Console.WriteLine("blogUser has been initialized"); foreach (var article in blogUser.Articles.Value) { Console.WriteLine(article.Title); }