.NET Delegates: A C# Bedtime Story中文版(下篇)

作者：Chris Sells

译者：荣耀

【译注：C#进阶文章。Chris Sells是《ATL Internals》一书作者之一。译文中所有程序调试环境均为Microsoft Visual Studio.NET 7.0 Beta2和 Microsoft .NET Framework SDK Beta2。代码就是文章，请仔细阅读代码J】

取得所有结果

     现在，peter终于松了一口气。他已经设法满足了所有的监听者，而且不会和特定实现紧密耦合。然而，他又注意到尽管boss和universe都为工作打了分，但他只得到了一个打分。【译注：请参见上节例子代码及译注】他希望能得到每一个监听者的评分结果。因此，他决定提取委托调用列表，以便手工分别调用它们：

public void DoWork()

{

//...

Console.WriteLine("Worker: work completed");

     if( completed != null)

{

foreach( WorkCompleted wc in completed.GetInvocationList())

{

int grade = wc();

Console.WriteLine("Worker grade= " + grade);

}

}

}

【译注：以下是本节描述之完整代码示例：

using System;

delegate void WorkStarted();     

delegate void WorkProgressing();

delegate int WorkCompleted();

class Worker

{

     public void DoWork()

     {

          Console.WriteLine("Worker: work started");

          if( started != null ) started();

          Console.WriteLine("Worker: work progressing");

          if( progressing != null ) progressing();

          Console.WriteLine("Worker: work completed");

        if( completed != null)

        {

            foreach( WorkCompleted wc in completed.GetInvocationList())

            {

                int grade = wc();

                Console.WriteLine("Worker grade= " + grade);

            }

        }

     }

     public event WorkStarted started ;

     public event WorkProgressing progressing;

     public event WorkCompleted completed;

}

class Boss

{

     public int WorkCompleted()

     {

          Console.WriteLine("Better...");

         return 4; /* out of 10 */

     }

}

class Universe

{

     static void WorkerStartedWork()

     {

          Console.WriteLine("Universe notices worker starting work");

     }

     static int WorkerCompletedWork()

     {

        &nb