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