C#常用的HttpGet HttpPost HttpDownload方法类

using System.Text;
using System.Net;
using System.IO;

namespace Test
{
    public class HttpMethod
    {
　　    public static string HttpGet(string URL)
        {
            HttpWebRequest req = (HttpWebRequest)WebRequest.Create(URL);
            //req.Proxy = new WebProxy(ProxyString, true); //true means no proxy
            　　　　WebResponse resp = null;
            req.Timeout = 2000;

            try
            {
                resp = (HttpWebResponse)req.GetResponse();
            }
            catch
            {
                req.Abort();
                req = null;
                return "timeout";
            }
            StreamReader sr = new StreamReader(resp.GetResponseStream(), Encoding.Default);
            string sReturn = sr.ReadToEnd().Trim();
            resp.Close(); sr.Close();
            return sReturn;
        }

        public static string HttpPost(string URL, string Parameters)
        {
            byte[] bytes = Encoding.Default.GetBytes(Parameters);

            ServicePointManager.DefaultConnectionLimit = 200;

            HttpWebRequest req = (HttpWebRequest)WebRequest.Create(URL);
            //req.Proxy = new WebProxy(ProxyString, true);
           　　　　 req.UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.8) Gecko/20051111 Firefox/1.5";
            req.Accept = "text/xml,application/xml,application/xhtml+xml,text/html";
            req.KeepAlive = false;
            //req.Referer = string.Format("https://10.116.24.197");
            　　　　req.ContentType = "application/x-www-form-urlencoded";
            req.Method = "POST";

            req.ContentLength = bytes.Length;

            req.Timeout = 3000;

            Stream os = null;
            try
            {
                os = req.GetRequestStream();
            }
            catch
            {
                req.Abort();
                req = null;
                return "timeout";
            }
            os.Write(bytes, 0, bytes.Length); //Push it out there
            os.Close();

            try
            {
                HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
                if (resp == null) return null;
                StreamReader sr = new StreamReader(resp.GetResponseStream(), Encoding.UTF8);
                string sReturn = sr.ReadToEnd().Trim();
                req.Abort();
                req = null;
                resp.Close();
                resp = null;
                sr.Close();

                return sReturn;
            }
            catch
            {
                req.Abort();
                req = null;
                return "timeout";
            }
        }



　　    public static void HttpDownloadFile(string url, string path)
        {
            HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
            WebResponse resp = null;

            req.Timeout = 3000;

            try
            {
                resp = (HttpWebResponse)req.GetResponse();
            }
            catch
            {
                req.Abort();
                req = null;
                return;
            }
            Stream respStm = resp.GetResponseStream();

            int end = path.LastIndexOf(@"\");

            string dir = path.Substring(0, end);

            if (!Directory.Exists(dir))
                Directory.CreateDirectory(dir);

            Stream stream = new FileStream(path, FileMode.Create);

            byte[] bArr = new byte[1024];
            int size = respStm.Read(bArr, 0, (int)bArr.Length);

            while (size > 0)
            {
                stream.Write(bArr, 0, size);
                size = respStm.Read(bArr, 0, (int)bArr.Length);
            }
            stream.Close();
            respStm.Close();
        }

    }

    Example:

    HttpMethod.HttpGet("http://10.116.24.197/test.php?data=This a Test");

    HttpMethod.HttpPost("http://10.116.24.197/test", "data=This a Test");

    HttpMethod.HttpDownloadFile("http://10.116.24.197/test/test.txt", @"D:\TestDownload\test.txt");
}