如何：使用字典儲存事件執行個體（C# 編程指南）

 

C# 編程指南 如何：使用字典儲存事件執行個體（C# 編程指南）  accessor-declarations 的一種用法是公開大量的事件但不為每個事件分配欄位，而是使用字典來儲存這些事件執行個體。這隻有在具有非常多的事件、但您預計大部分事件都不會實現時才有用。 樣本C#複製代碼public delegate void EventHandler1(int i);public delegate void EventHandler2(string s); publicclass PropertyEventsSample{    private System.Collections.Generic.Dictionary<string, System.Delegate> eventTable;     public PropertyEventsSample()    {        eventTable = new System.Collections.Generic.Dictionary<string, System.Delegate>();        eventTable.Add("Event1", null);        eventTable.Add("Event2", null);    }     public event EventHandler1 Event1    {        add        {            eventTable["Event1"] = (EventHandler1)eventTable["Event1"] + value;        }        remove        {            eventTable["Event1"] = (EventHandler1)eventTable["Event1"] - value;        }    }     public event EventHandler2 Event2    {        add        {            eventTable["Event2"] = (EventHandler2)eventTable["Event2"] + value;        }        remove        {            eventTable["Event2"] = (EventHandler2)eventTable["Event2"] - value;        }    }     internal void RaiseEvent1(int i)    {        EventHandler1 handler1;        if (null != (handler1 = (EventHandler1)eventTable["Event1"]))        {            handler1(i);        }    }     internal void RaiseEvent2(string s)    {        EventHandler2 handler2;        if (null != (handler2 = (EventHandler2)eventTable["Event2"]))        {            handler2(s);        }    }} publicclass TestClass{    publicstaticvoid Delegate1Method(int i)    {        System.Console.WriteLine(i);    }     publicstaticvoid Delegate2Method(string s)    {        System.Console.WriteLine(s);    }     staticvoid Main()    {        PropertyEventsSample p = new PropertyEventsSample();         p.Event1 += new EventHandler1(TestClass.Delegate1Method);        p.Event1 += new EventHandler1(TestClass.Delegate1Method);        p.Event1 -= new EventHandler1(TestClass.Delegate1Method);        p.RaiseEvent1(2);         p.Event2 += new EventHandler2(TestClass.Delegate2Method);        p.Event2 += new EventHandler2(TestClass.Delegate2Method);        p.Event2 -= new EventHandler2(TestClass.Delegate2Method);        p.RaiseEvent2("TestString");    }} 輸出2TestString  (來源：msdn )