典型的情况是,我们可能想要提出财产抵押物,例如,

    public event PropertyChangedEventHandler PropertyChanged; 
    protected void Notify(string property)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(property));
        }
    }

    public string UserNote
    {
        get { return _userNote; }
        set
        {
            _userNote = value;
            Notify("UserNote"); 
        }
    }

在我们现有的法典基础中,我看到一些情况,即财产抵押品被送去无效,以表明该物体的所有特性均已改变。 这似乎效率低下,似乎导致引发的事件比需要多得多。 这似乎还造成问题,即物体以循环方式相互更新。

这种做法是否好?

守则中的一项评论试图为之辩解......

//The purpose of this method is to wire up clients of NotificationBase that are also
//NotificationBases to *their* clients. Consider the following classes:     
         public class ClassA : NotificationBase
         {
             public int Foo
             {
                 get { return 123; }
                 set { Notify("Foo"); }
             }
         }

         public class ClassB : NotificationBase
         {
             ClassA A = new ClassA();
             public ClassB()
             {
                 A.PropertyChanged += AllChanged;
             }
             public void SetFoo()
             {
                 A.Foo = 456;
             }
         }

         public class ClassC
         {
             ClassB B = new ClassB();
             public ClassC()
             {
                 B.PropertyChanged += delegate { dosomething(); };
                 B.SetFoo(); // causes "dosomething" above to be called
             }
         }

        /// ClassB.SetFoo calls ClassA.Foo s setter, which calls ClassA.Notify("Foo").
        /// The event registration in ClassB s ctor causes ClassB.AllChanged to be called, which calls
        /// ClassB.Notify(null) - implying that ALL of ClassB s properties have changed.
        /// The event registration in ClassC s ctor causes the "dosomething" delegate to be called.
        /// So a Notify in ClassA is routed to ClassC via ClassB s PropertyChanged event.

        protected void AllChanged(Object sender, PropertyChangedEventArgs e)
        {
            Notify(null);
        }

任何想法都受到高度赞赏。

Regards, Fzzy