HttpWebRequest 的一个 异步封装[转]

直接贴代码了：

公共类：

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Data;
using System.Data.OleDb;
using System.Net;
using System.Xml;
using System.Net.Security;
using System.Security.Cryptography.X509Certificates;

[Serializable]
public class RequestInfo
{
    public RequestInfo(string url)
    {
        Url = url;
        AllowAutoRedirect = true;
    }
    public string Url { set; get; }
    public byte[] PostData { set; get; }
    public WebHeaderCollection Headers { set; get; }
    public bool AllowAutoRedirect { set; get; }
    public Dictionary<string, string> ExternalData { set; get; }
}

[Serializable]
public class ResponseInfo
{
    public RequestInfo RequestInfo { set; get; }
    public Stream ResponseContent { set; get; }
    public HttpStatusCode StatusCode { set; get; }
    public WebHeaderCollection Headers { set; get; }
    public string GetString(Encoding coding)
    {
        StringBuilder str = new StringBuilder();
        Stream sr = ResponseContent;
        sr.Seek(0, SeekOrigin.Begin);
        byte[] data = new byte[1024 * 1024];
        int readcount = sr.Read(data, 0, data.Length);
        while (readcount > 0)
        {
            str.Append(coding.GetString(data, 0, readcount));
            readcount = sr.Read(data, 0, data.Length);
        }
        return str.ToString();
    }
}

internal class StateObject
{
    public byte[] Buffer { set; get; }
    public ResponseInfo ResponseInfo { set; get; }
    public Stream ReadStream { set; get; }
    public HttpWebRequest HttpWebRequest { set; get; }
    public Action<ResponseInfo> Action { set; get; }

}

public class RequestHttpWebRequest
{
    static RequestHttpWebRequest()
    {
        ServicePointManager.DefaultConnectionLimit = 100;
    }
    public RequestHttpWebRequest()
    {
        ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);
    }
    private bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
    {
        //直接确认，否则打不开  
        return true;
    }
    public void GetResponseAsync(RequestInfo info, Action<ResponseInfo> act)
    {
        HttpWebRequest webRequest;
        StateObject state;
        InitWebRequest(info, act, out webRequest, out state);
        try
        {
            if (info.PostData != null && info.PostData.Length > 0)
            {
                webRequest.Method = "POST";
                webRequest.ContentType = "application/x-www-form-urlencoded";
                webRequest.BeginGetRequestStream(EndRequest, state);
            }
            else
            {
                webRequest.BeginGetResponse(EndResponse, state);
            }

        }
        catch (Exception ex)
        {
            HandException(ex, state);
        }
    }
    
    public void EndRequest(IAsyncResult ar)
    {
        StateObject state = ar.AsyncState as StateObject;
        try
        {
            HttpWebRequest webRequest = state.HttpWebRequest as HttpWebRequest;
            using (Stream stream = webRequest.EndGetRequestStream(ar))
            {
                byte[] data = state.ResponseInfo.RequestInfo.PostData;
                stream.Write(data, 0, data.Length);
            }
            webRequest.BeginGetResponse(EndResponse, state);

        }
        catch (Exception ex)
        {
            HandException(ex, state);
        }
    }
    
    public void EndResponse(IAsyncResult ar)
    {
        StateObject state = ar.AsyncState as StateObject;
        try
        {
            HttpWebResponse webResponse = state.HttpWebRequest.EndGetResponse(ar) as HttpWebResponse;
            state.ResponseInfo.StatusCode = webResponse.StatusCode;
            state.ResponseInfo.Headers = new WebHeaderCollection();
            foreach (string key in webResponse.Headers.AllKeys)
            {
                state.ResponseInfo.Headers.Add(key, webResponse.Headers[key]);
            }
            state.ReadStream = webResponse.GetResponseStream();
            state.ReadStream.BeginRead(state.Buffer, 0, state.Buffer.Length, ReadCallBack, state);
        }
        catch (Exception ex)
        {
            HandException(ex, state);

        }
    }
    void ReadCallBack(IAsyncResult ar)
    {
        StateObject state = ar.AsyncState as StateObject;
        try
        {
            int read = state.ReadStream.EndRead(ar);
            if (read > 0)
            {
                state.ResponseInfo.ResponseContent.Write(state.Buffer, 0, read);
                state.ReadStream.BeginRead(state.Buffer, 0, state.Buffer.Length, ReadCallBack, state);
            }
            else
            {
                state.ReadStream.Close();
                state.HttpWebRequest.Abort();
                if (state.Action != null)
                {
                    state.Action(state.ResponseInfo);
                }
            }
        }
        catch (Exception ex)
        {
            HandException(ex, state);
        }
    }
    private void InitWebRequest(RequestInfo info, Action<ResponseInfo> act, out HttpWebRequest webRequest, out StateObject state)
    {

        webRequest = HttpWebRequest.CreateDefault(new Uri(info.Url)) as HttpWebRequest;
        webRequest.KeepAlive = true;
        webRequest.AllowAutoRedirect = info.AllowAutoRedirect;
        if (info.Headers != null && info.Headers.Count > 0)
        {
            foreach (string key in info.Headers.Keys)
            {
                webRequest.Headers.Add(key, info.Headers[key]);
            }
        }
        //webRequest.Proxy = WebProxy.GetDefaultProxy();
        //webRequest.Proxy.Credentials = CredentialCache.DefaultCredentials;  
        // webResponse.Headers.Get("Set-Cookie");
        state = new StateObject
        {
            Buffer = new byte[1024 * 1024],
            HttpWebRequest = webRequest,
            Action = act,
            ResponseInfo = new ResponseInfo
            {
                RequestInfo = info,
                ResponseContent = new MemoryStream()
            }
        };
    }

    private void HandException(Exception ex, StateObject state)
    {
        string message = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss") + " : " + state.ResponseInfo.RequestInfo.Url + " : " + ex.Message;
        Console.WriteLine(message);
    }
}

 

测试代码：

index.aspx

    public partial class index : System.Web.UI.Page
    {
        private static string MESSAGE_TXT_PATH = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "async_web_request_log.txt");

        protected void Page_Load(object sender, EventArgs e)
        {
            if(!IsPostBack)
            {
                SendWebRequestToBaidu();
                SendWebRequestToHandle();
            }
        }

        protected void SendWebRequestToBaidu()
        {
            RequestHttpWebRequest asyncWebRequest = new RequestHttpWebRequest();
            asyncWebRequest.GetResponseAsync(new RequestInfo("http://www.baidu.com"), c =>
                {
                    StringBuilder sbTextAppender = new StringBuilder("===============================================\r\n\r\n\r\n");
                    foreach (string headKey in c.Headers.AllKeys)
                    {
                        sbTextAppender.AppendFormat("Key:{0}, Value:{1}\r\n\r\n", headKey, c.Headers[headKey]);
                    }
                    File.AppendAllText(MESSAGE_TXT_PATH, sbTextAppender.ToString());
                });
        }

        protected void SendWebRequestToHandle()
        {
            string url = Request.Url.Scheme + "://" + Request.Url.Authority + "/async_web_response.ashx?id=13";
            RequestHttpWebRequest asyncWebRequest = new RequestHttpWebRequest();
            asyncWebRequest.GetResponseAsync(new RequestInfo(url) { PostData = Encoding.UTF8.GetBytes("name=张三") }, c =>
            {
                string responseText = c.GetString(Encoding.UTF8);
                File.AppendAllText(MESSAGE_TXT_PATH, responseText);
            });
        }
    }

async_web_response.ashx

    /// <summary>
    /// async_web_response 的摘要说明
    /// </summary>
    public class async_web_response : IHttpHandler
    {

        public void ProcessRequest(HttpContext context)
        {
            context.Response.ContentType = "text/plain";

            System.Threading.Thread.Sleep(3000); 

            string id = context.Request.QueryString["id"];

            string name = context.Request.Form["name"];

            context.Response.Write(string.Format("id:{0}, name:{1}", id, name));
        }

        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }

 

转自：http://www.cnblogs.com/majiang/archive/2013/04/28/3049622.html

谢谢浏览！