如何在调用WCF服务之前弹出一个确认对话框？

昨天有人在微博上问我如下一个问题：

老蒋，客户端调用wcf的一个接口函数时，有没有什么办法可以先弹出一个确认框，确认后再执行调用。因为这个接口函数再很多地方都执行了调用，所以我想在某个入口进行统一地弹出一个确认框...

class InvocationConfirmationInteractiveChannelInitializer : IInteractiveChannelInitializer

   2: {

;

object state)

   5:     {

, MessageBoxButtons.YesNo) == DialogResult.No;

new SimpleAsynsResult(cancel);

   8:     }

   9:  

void EndDisplayInitializationUI(IAsyncResult result)

  11:     {

  12:         SimpleAsynsResult asyncResult = (SimpleAsynsResult)result;

bool)asyncResult.AsyncState)

  14:         {

);

  16:         }

  17:     }

  18: }

  19:  

class SimpleAsynsResult:IAsyncResult

  21: {

object state)

  23:     {

this.AsyncState = state;

  25:     }

  26:  

private set; }

private set; }

bool CompletedSynchronously

  30:     {

true; }

  32:     }

bool IsCompleted

  34:     {

true; }

  36:     }

  37: }