HttpRequest重写，解决资源战胜/链接超时/分块下载事件通知 问题。

/*************************************************************************************
* 文 件 名： WebRequest.cs
* 创建时间： 2015-06-18
* 作    者： Sam Shum ([e-mail])
* 说    明： 解决WebHttpRequest下载网页数据出现问题  
* 修改时间： 2015-06-19
* 修 改 人： Sam Shum
*************************************************************************************/

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.IO;

using System.IO.Compression;

using System.Linq;

using System.Net;

using System.Text;

using System.Web;

namespace S.Sams.Common

{

    public class HttpRequest

    {

        public HttpRequest()

        {

            //string Url = "http://localhost:5192/api/Cab/5";

            //string httpMethod = "PUT";

            //string httpContent = "{'Name': 'B90', 'Color': 'Green', 'Height': 1590, 'Width': 4500 }";

            //Encoding httpCode = Encoding.Default;

            //Console.WriteLine(Get(Url, httpMethod, httpContent, httpCode));

            setEncoding = Encoding.Default;

        }

        public HttpRequest(string url, string method) : base()

        {

            setUrl = url;

            setMethod = method;

        }

        /// <summary>

        /// 服务请求地址 http://www.aaa.com/

        /// </summary>

        public string setUrl { get; set; }

        /// <summary>

        /// 服务请求方法：GET/POST/PUT/DELETE

        /// </summary>

        public string setMethod { get; set; }

        /// <summary>

        /// 设置服务请求数据类型

        /// </summary>

        [DefaultValue("text/html")]

        public string setContentType { get; set; }

        /// <summary>

        /// 设置服务页面编码

        /// </summary>

        public Encoding setEncoding { get; set; }

        public delegate void DownloadStartDelegate(int httpStatusCode);

        public delegate void DownloadProcessDelegate(long totalLength, long DownloadedByte, float percent);

        public delegate void DownloadEndDelegate(long totalLength);

        public event DownloadStartDelegate DownloadStart;

        public event DownloadProcessDelegate DownloadProcess;

        public event DownloadEndDelegate DownloadEnd;

        public string Get()

        {

            return Get(setUrl);

        }

        public string Get(string setUrl)

        {

            return Get(setUrl, "GET", null, setEncoding);

        }

        public string Get(string setUrl, string httpContent)

        {

            return Get(setUrl, "POSE", httpContent, setEncoding);

        }

        public string Get(string Url, string httpMethod, string httpContent, Encoding httpCode)

        {

            if (string.IsNullOrWhiteSpace(Url) || string.IsNullOrWhiteSpace(httpMethod))

            {

                throw new ArgumentException("Url or HttpMethod 参数不能为空！");

            }

            GC.Collect();

            StringBuilder content = new StringBuilder();

            HttpWebRequest request = null;

            HttpWebResponse response = null;

            StreamWriter sw = null;

            try

            {

                ServicePointManager.DefaultConnectionLimit = ;

                request = WebRequest.Create(Url) as HttpWebRequest;

                request.Method = httpMethod;

                request.AllowAutoRedirect = true;

                request.KeepAlive = false;

                request.Accept = "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 2.0.50727; Maxthon 2.0)";

                request.ContentType = setContentType; //"application/octet-stream";

                request.Proxy = null;

                if (httpContent != null && !string.IsNullOrWhiteSpace(httpContent))

                {

                    using (sw = new StreamWriter(request.GetRequestStream()))

                    {

                        sw.Write(httpContent);

                    }

                }

                using (response = request.GetResponse() as HttpWebResponse)

                {

                    if (this.DownloadStart != null)

                        this.DownloadStart((int)response.StatusCode);

                    Stream stream = response.GetResponseStream();

                    if (response.ContentEncoding.ToLower().Contains("gzip"))

                        stream = new GZipStream(stream, CompressionMode.Decompress);

                    float percent = ;

                    long totalDownloadedByte = ;

                    long totalBytes = response.ContentLength;

                    while (stream.CanRead)

                    {

                        byte[] buffer = new byte[];

                        int canrds = stream.Read(buffer, , );

                        totalDownloadedByte = canrds + totalDownloadedByte;

                        percent = (float)totalDownloadedByte / (float)totalBytes * ;

                        if (DownloadProcess != null && canres > 0)

                            DownloadProcess(totalBytes, totalDownloadedByte, percent);

                        if (canrds == )

                            break;

                        content.Append(httpCode.GetString(buffer));

                    }

                    if (DownloadEnd != null)

                        DownloadEnd(totalBytes);

                    stream.Dispose();

                }

            }

            finally

            {

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

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

                if(sw != null) sw.Dispose();

            }

            GC.SuppressFinalize(this);

            return content.ToString();

            /*

            Response.Write(Guid.NewGuid().ToString() + "<hr />");

            Response.Write(Guid.NewGuid().ToString("N") + "<hr />");

            Response.Write(GetHttpContent);

            Response.End();

            */

        }

    }

}