HttpWebRequest的CLOSE_WAIT问题

Question

我有一个应用程序同时连接到许多网站,并通过http下载大文件.

当我检查系统时TcpView,CLOSE_WAIT状态有很多连接.我的代码是这样的:

try
{
    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
    HttpWebResponse response = (HttpWebResponse)request.GetResponse();
}
catch
{
    if (response != null)
        response.Close();
}

Stream stream = Response.GetResponseStream();

// read stream until an error happens or we reach end of stream. Then:

if (request != null)
    request.Abort();

if (response != null)
    response.Close();

为什么我在CLOSE_WAIT州仍然有很多联系？