什么是正确的实现IAsyncResult接口的？ [英] What is a proper implementation of the IAsyncResult interface?

问题描述

我寻找到增加一些灵活性，我已经创建了它建立到远程主机的连接的类，然后进行信息交换（握手）。目前的实现提供了一个连接功能，建立连接，然后阻止等待一个ManualResetEvent的，直到双方​​已经完成了握手。

I'm looking into adding some flexibility to a class that I've created which establishes a connection to a remote host and then performs an exchange of information (a handshake). The current implementation provides a Connect function which establishes the connection and then blocks waiting on a ManualResetEvent untill the two parties have completed the handshake.

下面是一个什么样叫我的类看起来像一个例子：

Here's an example of what calling my class looks like:

// create a new client instance
ClientClass cc = new ClientClass("address of host");
bool success = cc.Connect();  // will block here until the
                              //  handshake is complete
if(success)
{

}

......这里的的类在内部做什么的过于简单化的高级视图：

..and here's an oversimplified high-level view of what the class does internally:

class ClientClass
{
    string _hostAddress;
    ManualResetEvent _hanshakeCompleted;
    bool _connectionSuccess;

    public ClientClass(string hostAddress)
    {
        _hostAddress = hostAddress;            
    }

    public bool Connect()
    {
        _hanshakeCompleted = new ManualResetEvent(false);            
        _connectionSuccess = false;

        // start an asynchronous operation to connect
        //  ...
        //  ...

        // then wait here for the connection and
        //  then handshake to complete
        _hanshakeCompleted.WaitOne();

        // the _connectionStatus will be TRUE only if the
        //  connection and handshake were successful
        return _connectionSuccess;
    }

    // ... other internal private methods here
    // which handle the handshaking and which call
    // HandshakeComplete at the end

    private void HandshakeComplete()
    {
        _connectionSuccess = true;
        _hanshakeCompleted.Set();
    }
}

我在寻找进入实施 .NET经典的异步模式这个类。在此过程中，我将提供BeginConnect和EndConnect功能，并允许类的用户编写code是这样的：

I'm looking into implementing the .NET Classic Async Pattern for this class. In doing so, I would provide BeginConnect and EndConnect functions, and allow the users of the class to write code like this:

ClientClass cc = new ClientClass("address of host");
cc.BeginConnect(new AsyncCallback(ConnectCompleted), cc);
// continue without blocking to this line

// ..

void ConnectCompleted(IAsyncResult ar)
{
    ClientClass cc = ar.AyncState as ClientClass;
    try{
        bool success = cc.EndConnect(ar);
        if(success)
        {
             // do more stuff with the 
             //  connected Client Class object
        }
    }
    catch{
    }
}

为了能够提供该API我需要创建实现IAsyncResult接口由BeginConnect函数返回一个类，并且分别被传递到EndConnect功能

In order to be able to provide this API I need to create a class that implements the IAsyncResult interface to be returned by the BeginConnect function, and to be passed into the EndConnect function respectively.

现在，我的问题是：什么是实现一类IAsyncResult接口有道

一个显而易见的解决方案是创建一个委托具有匹配签名的连接功能，然后异步调用使用的BeginInvoke该委托 - EndInvoke会，但不是我要找的（这不是很有效）。

One obvious solution would be to create a delegate with a matching signature for the Connect function and then invoke that delegate asynchronously using BeginInvoke - EndInvoke but that is not what I'm looking for (it's not very efficient).

我有我怎么能做到这一点粗略的想法，但偷看了.NET框架内他们是如何实现这个模式在一些地方后，我觉得这将是明智的询问，看看是否有人有这个成功，如果是这样做的有什么问题地区要特别注意。

I have a rough idea of how I could do it but after peeking inside the .NET framework at how they implement this pattern in some places I felt it would be wise to ask and see if anybody has done this successfully and if so what are the problem areas to pay special attention to.

谢谢！

推荐答案

• 杰弗里里氏（MSDN杂志）
• 微软WCF样品
• <一个href="http://blogs.msdn.com/b/nikos/archive/2011/03/14/how-to-implement-iasyncresult-in-another-way.aspx"相对=nofollow>尼科Schuessler （MS员工）
• 在谷歌IAsyncResult的执行情况的详细...

• Jeffery Richter (MSDN Magazine)
• Microsoft's WCF Samples
• Niko Schuessler (MS employee)
• Google "IAsyncResult Implementation" for more...

您也有很多实现的BCL（如 System.Runtime.Remoting.Messaging.AsyncResult ） - 使用反射器或引用来源检查出来

You also have many implementations in the BCL (e.g. System.Runtime.Remoting.Messaging.AsyncResult) - use reflector or the reference source to check them out.

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