MVVM命令绑定原理

跟据网上前辈们的资料。了解到命令在MVVM绑定有三种行式。

1.DelegateCommand

2.RelayCommand

3.AttachbehaviorCommand

 /// <summary>
     /// Delegatecommand，继承一个命令接口。
     /// </summary>
     public class DelegateCommand : ICommand
     {
         Func<object, bool> canExecute;
         Action<object> executeAction;
         bool canExecuteCache;

         public DelegateCommand(Action<object> executeAction, Func<object, bool> canExecute)
         {
             this.executeAction = executeAction;
             this.canExecute = canExecute;
         }

         #region ICommand Members

         public bool CanExecute(object parameter)
         {
             bool temp = canExecute(parameter);

             if (canExecuteCache != temp)
             {
                 canExecuteCache = temp;
                 if (CanExecuteChanged != null)
                 {
                     CanExecuteChanged(this, new EventArgs());
                 }
             }

             return canExecuteCache;
         }

         public event EventHandler CanExecuteChanged;

         public void Execute(object parameter)
         {
             executeAction(parameter);
         }

         #endregion
     }

在代码中不难看出这两个变量。
Func<object, bool> canExecute;
Action<object> executeAction;

具体这两种变量的含义网上有很多。可以百度。http://www.cnblogs.com/fish124423/archive/2012/05/16/2504304.html