一步一步学习MVVM一 查询篇

关于MVVM模式概念就不讲了，网上一大堆，而且超详细。 先描述一下整体解决方案：把服务器信息从服务器端取出来显示在客户端，

Model层负责取数据并序列化成对象，ViewModel负责绑定到View,

效果图：

Model层负责数据

实体Server实现

INotifyPropertyChanged接口，当属性改变时通知界面。

 1  #region ip
 2         private string _ip;
 3 
 4         public string IP
 5         {
 6             get { return _ip; }
 7             set
 8             {
 9                 if (_ip != value)
10                 {
11                     _ip = value;
12                     OnPropertyChanged("IP");
13                 }
14             }
15         }
16         #endregion
17 
18         #region 名称
19         private string _Name;
20 
21         public string Name
22         {
23             get { return _Name; }
24             set
25             {
26                 if (_Name != value)
27                 {
28                     _Name = value;
29                     OnPropertyChanged("Name");
30                 }
31 
32             }
33         }
34         #endregion
35 
36         public event PropertyChangedEventHandler PropertyChanged;
37 
38         private void OnPropertyChanged(string propertyName)
39         {
40             if (PropertyChanged != null)
41                 PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
42         }

取Server数据的方法，实际可改为从WCF中取数据，

         private ObservableCollection<Server> serverList;
2         public ObservableCollection<Server> GetServerList()
3         {
4             serverList = new ObservableCollection<Server>();
5             serverList.Add(new Server { IP="192.168.1.1",Name="张三的电脑"});
6             serverList.Add(new Server { IP = "192.168.1.2", Name = "李四的电脑" });
7             serverList.Add(new Server { IP = "192.168.1.1", Name = "王五的电脑" });
8             return serverList;
9         }

所有的业务集中在ViewModel里面，提供View绑定需要的各种属性和集合。

 1     public class ServerViewModel:INotifyPropertyChanged
 2     {
 3         private ServerModel sm;
 4         private Server currentServer;
 5         public Server CurrentServer
 6         {
 7             get { return currentServer; }
 8             set
 9             {
10                 CurrentServer = value;
11                 this.OnPropertyChanged("CurrentServer");
12             }
13         }
14 
15         public ServerViewModel()
16         { 
17             sm=new ServerModel();
18             serverList = sm.GetServerList();
19         }
20 
21         private ObservableCollection<Server> serverList;
22         public ObservableCollection<Server> ServerList 
23         {
24             get { return serverList; }
25             set 
26             { 
27                 serverList = value;
28                 this.OnPropertyChanged("ServerList");
29             }
30         }
31 
32         public event PropertyChangedEventHandler PropertyChanged;
33 
34         private void OnPropertyChanged(string propertyName)
35         {
36             if (PropertyChanged != null)
37                 PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
38         }
39     }

View中代码最简洁：

        private ServerViewModel svm;
        public MainPage()
        {
            InitializeComponent();
            svm = new ServerViewModel();
            this.DataContext = svm;
        }

Demo下载