当我们用MVVM的时候要实现INotifyPropertyChanged,每次都要实现这个接口比较麻烦，所以基类的作用就体现出来了。代码如下：
public class ViewModelBase : INotifyPropertyChanged, IDisposable
{
public event PropertyChangedEventHandler PropertyChanged;
public bool IsInDesignMode;
/// <summary> 显示名称 </summary>
public virtual string DisplayName { get; protected set; } #region 构造 public ViewModelBase()
{ }
#endregion private void OnPropertyChanged(string propertyName)
{
if (this.PropertyChanged != null)
{
this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
private static string GetProperyName(string methodName)
{
if (methodName.StartsWith("get_") || methodName.StartsWith("set_") ||
methodName.StartsWith("put_"))
{
return methodName.Substring(4);
}
throw new Exception(methodName + " not a method of Property");
} protected void SetProperty<T>(ref T name, T value)
{
if (object.Equals(name, value)) return;
name = value;
string propertyName = GetProperyName(new System.Diagnostics.StackTrace(true).GetFrame(1).GetMethod().Name);
this.OnPropertyChanged(propertyName);
} #region IDisposable Members
public void Dispose()
{
this.OnDispose();
}
/// <summary>
/// 若支持IDisposable，请重写此方法，当被调用Dispose时会执行此方法。
/// </summary>
protected virtual void OnDispose()
{
}
#endregion
}
public class CommandBase : System.Windows.Input.ICommand
{
private Action<Object> _doWork;
private readonly Func<object, bool> _canExecute; /// <summary>
/// 实例化一个CommandBase对象
/// </summary>
/// <param name="doWork">委托一个有object类型参数的命令执行函数</param>
/// <param name="canExecute">委托一个有object类型参数的命令是否能被执行的函数（可选）</param>
/// <exception cref="ArgumentNullException">参数command不可以为null引用</exception>
public CommandBase(Action<object> doWork, Func<object, bool> canExecute = null)
{
if (doWork == null)
throw new ArgumentNullException("doWork"); _canExecute = canExecute;
_doWork = doWork;
}
public bool CanExecute(Object parameter)
{
return true;
}
public void Execute(Object parameter)
{
if (this._doWork != null)
this._doWork(parameter);
}
public event EventHandler CanExecuteChanged
{
add { }
remove { }
}
}
使用方式如下，例：
public class TestViewModel : ViewModelBase
{
public TestViewModel()
{
this.LoadCommand = new CommandBase((Object parameter) => Loading());
}
#region 属性 private string _name; /// <summary> 是否可用 </summary>
public string IsEnable
{
get { return _name; }
set
{
base.SetProperty<string>(ref this._name, value);
}
}
#endregion #region 命令 /// <summary>
/// 窗口加载命令
/// </summary>
public ICommand LoadCommand { get; set; }
#endregion #region 方法 /// <summary>
/// 初始化方法
/// </summary>
public void Loading()
{ }
#endregion
}
看了例子后，是不是感觉很简单呢？详细的测试代码会再后续的文章中提供给大家参考。