Windows 8開發入門（二十一） Windows 8 下進行MVVM開發

在本文中將示範如何在Windows 8進行MVVM開發，首先我們準備兩個輔助類如下：

ViewModeBase類 ：

public class ViewModeBase : INotifyPropertyChanged    {        public event PropertyChangedEventHandler PropertyChanged;        /// <summary>        /// 屬性變化時觸發事件        /// </summary>        /// <param name="propertyName"></param>        protected void OnPropertyChanged( string propertyName )        {            var handler = this.PropertyChanged;            if ( handler != null )            {                handler( this, new PropertyChangedEventArgs( propertyName ) );            }        }    }

DelegateCommand類：

public class DelegateCommand : ICommand    {        private readonly Action m_exeAction;        private readonly Func<bool> m_canExeAction;            /// <summary>        /// 建構函式        /// </summary>        /// <param name="executeAction"></param>        /// <param name="canExecuteAction"></param>        public DelegateCommand(Action executeAction, Func<bool> canExecuteAction)        {            m_exeAction = executeAction;            m_canExeAction = canExecuteAction;        }            /// <summary>        /// 建構函式        /// </summary>        /// <param name="executeAction"></param>        /// <param name="canExecuteAction"></param>        public DelegateCommand(Action executeAction)            : this(executeAction, null)        {        }        /// <summary>        /// 判斷是否執行操作        /// </summary>        /// <param name="parameter"></param>        /// <returns></returns>        public bool CanExecute(object parameter)        {            if (m_canExeAction != null)            {                return m_canExeAction();            }            return true;        }        /// <summary>        /// 是否執行操作的變更發生時        /// </summary>        public event EventHandler CanExecuteChanged;            /// <summary>        /// 執行操作的內容，可以變為Action行為        /// </summary>        /// <param name="parameter"></param>        public void Execute(object parameter)        {            if (CanExecute(parameter))            {                m_exeAction();            }        }            protected void OnCanExecuteChanged(object sender, EventArgs args)        {            var handler = CanExecuteChanged;            if ( handler != null )            {                handler( this, EventArgs.Empty );            }        }            public void RaiseCanExecuteChanged()        {            OnCanExecuteChanged(this, EventArgs.Empty);        }    }