1  private DelegateCommand<object> registerCommand { get; private set; }
 2         public ICommand RegisterCommand
 3         {
 4             get
 5             {
 6                 if (registerCommand == null)
 7                 {
 8                     registerCommand = new DelegateCommand<object>(OnRegisterExcute, this.CanRegister);
 9                 }
10 
11                 return registerCommand;
12             }
13         }
14 
15         bool CanRegister(object sender)
16         {
17             if (!this.IsValid)    //IsValid是一个返回bool型的方法
18                 return false;
19             
20             return true;
21         }
22 
23         void OnRegisterExcute(object sender)
24         {
25             MessageBox.Show("注册中...");
26         }