自定义延迟加载类

延迟加载类

 1     public class LazyLoader<TModel> where TModel:class
 2     {
 3         TModel _data;
 4         Func<TModel> _loadDataFunc = null;
 5         bool _loaded = false;
 6         public LazyLoader():this(null){ }
 7         public LazyLoader(Func<TModel> loadDataFunc) 
 8         {
 9             _loadDataFunc = loadDataFunc;
10             _data = null;
11             _loaded = false;
12         }
13         public TModel QueryData() 
14         {
15             if (!_loaded && _loadDataFunc != null)
16             {
17                 _data = _loadDataFunc();
18             }
19             return _data;
20         }
21         public void SetData(TModel value) 
22         {
23             _data = value;
24             _loaded = true;
25         }
26     }
LazyLoader

使用方法（简单举列）

比如员工菜单 可能你再使用这个员工对象的时候并不需要去加载他的菜单 当你要用的时候再加载 这时候就需要延迟加载了 

 1     public class Employee
 2     {
 3         public LazyLoader<IEnumerable<Menu>> _menus;
 4         public Employee(Guid employeeId, string employeeNo, string name, string password, string email, string phone, bool enabled,  bool isAdministrtor, DateTime registerDate, string remark, string ipLimitation)
 5         {
 6             EmployeeId = employeeId;
 7             EmployeeNo = employeeNo;
 8             Name = name;
 9             Password = password;
10             Email = email;
11             Phone = phone;
12             Enabled = enabled;
13             IsAdministrator = isAdministrtor;
14             RegisterDate = registerDate;
15             Remark = remark;
16             IpLimitation = ipLimitation;
17             _menus = new LazyLoader<IEnumerable<Menu>>(() => SystemResourceService.QueryMenusByEmployeeId(employeeId));
18         }
19 
20         public Guid EmployeeId { get; private set; }
21         public string EmployeeNo { get; private set; }
22         public string Name { get; private set; }
23         public string Password { get; private set; }
24         public string Email { get; private set; }
25         public string Phone { get; private set; }
26         public bool Enabled { get; set; }
27         public bool IsAdministrator { get; private set; }
28         public DateTime RegisterDate { get; private set; }
29         public string Remark { get; private set; }
30         public string IpLimitation { get; set; }
31         public object Id
32         {
33             get { return EmployeeId; }
34         }
35     }
Employee

 

posted @ 2015-05-04 20:44  刘小吉  阅读(298)  评论(0)  编辑  收藏  举报