Question

在下面的代码中，我有一个List对象。我想迭代每一个并为每个Item对象的一个属性赋值。要获取该值，我需要调用WCF服务的异步方法。

当我对WCF服务的调用完成时，如何获取该数据并将其分配给itemsList中的当前实例（i）？有没有办法从我的xxxCompleted事件中访问i？

private void SomeMethod()
{
    List<Item> itemsList = GetItems();

    foreach(Item i in itemsList)
    {  
      MyClient client = new MyClient();
      client.GetSomeValueCompleted += client_GetSomeValueCompleted;
      client.GetSomeValueAsync(i.ID);
    } 
}   

private void client_GetSomeValueCompleted(object sender, GetSomeValueEventArgs e)
{
  int id = e.Result;
  //  how do I assign this ID to my itemsList object, i  ???
}

Answer 1

您可以在异步方法调用中将MyClient类的实例作为userstate传递。

看看这个link


private void SomeMethod()
{    
   List itemsList = GetItems();    
   foreach(Item i in itemsList)    
   {        
      MyClient client = new MyClient();      
      client.GetSomeValueCompleted += client_GetSomeValueCompleted;      
      client.GetSomeValueAsync(i.ID, client);
   } 
}   

private void client_GetSomeValueCompleted(object sender, GetSomeValueEventArgs e)
{  
   int id = e.Result;  

   //  how do I assign this ID to my itemsList object, i  ???
   (e.UserState as MyClient).ID = id;
}

从foreach循环中的WCF异步方法获取数据

1 个答案: