简单的MVVM计算器实例

【实例简介】

简单的MVVM计算器实例

【实例截图】

【核心代码】

namespace Commands
{
    public class DelegateCommand : ICommand
    {
        private Action<object> executeCommand;

        public Action<object> ExecuteCommand
        {
            get { return executeCommand;}
            set { executeCommand = value; }
        }

        private Func<object, bool> canExecuteCommand;

        public Func<object, bool> CanExecuteCommand
        {
            get { return canExecuteCommand; }
            set { canExecuteCommand = value; }
        }

        public DelegateCommand(Action<object> excuteCommand, Func<object, bool> canExcuteCommand)
        {
            this.executeCommand = excuteCommand;
            this.canExecuteCommand = canExcuteCommand;
        }

        public event EventHandler CanExecuteChanged;

        public bool CanExecute(object parameter)
        {
            if (CanExecuteCommand != null)
            {
                return this.CanExecuteCommand(parameter);
            }
            else
            {
                return true;
            }
        }

        public void Execute(object parameter)
        {
            if(this.ExecuteCommand != null)
            {
                this.ExecuteCommand(parameter);
            }
        }

        public void RaiseCanExecuteChanged()
        {
            if (CanExecuteCommand != null)
            {
                CanExecuteChanged(this,EventArgs.Empty);
            }
        }
    }
}