using System.Net; using System.Net.Security; using System.Security.Cryptography.X509Certificates; using System.Text; using System.Text.RegularExpressions; using System.Threading.Tasks; namespace WinFormsApp /// /// C# HttpWebRequest 上传大文件 /// public class Class1 public static string ExecutePost(UploadParameterType parameter) using (MemoryStream memoryStream = new MemoryStream()) // 1.分界线 string boundary = string.Format("----{0}", DateTime.Now.Ticks.ToString("x")), // 分界线可以自定义参数 beginBoundary = string.Format("--{0}\r\n", boundary), endBoundary = string.Format("\r\n--{0}--\r\n", boundary); byte[] beginBoundaryBytes = parameter.Encoding.GetBytes(beginBoundary), endBoundaryBytes = parameter.Encoding.GetBytes(endBoundary); // 2.组装开始分界线数据体 到内存流中 memoryStream.Write(beginBoundaryBytes, 0, beginBoundaryBytes.Length); // 3.组装 上传文件附加携带的参数 到内存流中 if (parameter.PostParameters != null && parameter.PostParameters.Count > 0) foreach (KeyValuePair keyValuePair in parameter.PostParameters) string parameterHeaderTemplate = string.Format("Content-Disposition: form-data; name=\"{0}\"\r\n\r\n{1}\r\n{2}", keyValuePair.Key, keyValuePair.Value, beginBoundary); byte[] parameterHeaderBytes = parameter.Encoding.GetBytes(parameterHeaderTemplate); memoryStream.Write(parameterHeaderBytes, 0, parameterHeaderBytes.Length); if (parameter.FileNameValue != null)//如果没有你文件则跳过本检测 //4.组装文件头数据体 到内存流中 string fileHeaderTemplate = string.Format("Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\nContent-Type: application/octet-stream\r\n\r\n", parameter.FileNameKey, parameter.FileNameValue); byte[] fileHeaderBytes = parameter.Encoding.GetBytes(fileHeaderTemplate); memoryStream.Write(fileHeaderBytes, 0, fileHeaderBytes.Length); // 5.组装文件流 到内存流中 byte[] buffer = new byte[1024 * 1024 * 1]; int size = parameter.UploadStream.Read(buffer, 0, buffer.Length); while (size > 0) memoryStream.Write(buffer, 0, size); size = parameter.UploadStream.Read(buffer, 0, buffer.Length); // 6.组装结束分界线数据体 到内存流中 memoryStream.Write(endBoundaryBytes, 0, endBoundaryBytes.Length); //7.获取二进制数据 byte[] postBytes = memoryStream.ToArray(); // 8.HttpWebRequest 组装 HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(new Uri(parameter.Url, UriKind.RelativeOrAbsolute)); webRequest.Method = "POST"; webRequest.Timeout = 10000; webRequest.ContentType = string.Format("multipart/form-data; boundary={0}", boundary); webRequest.ContentLength = postBytes.Length; if (Regex.IsMatch(parameter.Url, "^https://")) ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls; ServicePointManager.ServerCertificateValidationCallback = CheckValidationResult; // 9.写入上传请求数据 using (Stream requestStream = webRequest.GetRequestStream()) requestStream.Write(postBytes, 0, postBytes.Length); requestStream.Close(); // 10.获取响应 using (HttpWebResponse webResponse = (HttpWebResponse)webRequest.GetResponse()) using (StreamReader reader = new StreamReader(webResponse.GetResponseStream(), parameter.Encoding)) string body = reader.ReadToEnd(); reader.Close(); return body; static bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors) return true;

*、UploadParameterType.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace WinFormsApp
    /// <summary>
    /// 上传文件 - 请求参数类
    /// </summary>
    public class UploadParameterType
        public UploadParameterType()
            FileNameKey = "fileName";
            Encoding = Encoding.UTF8;
            PostParameters = new Dictionary<string, string>();
        /// <summary>
        /// 上传地址
        /// </summary>
        public string Url { get; set; }
        /// <summary>
        /// 文件名称key
        /// </summary>
        public string FileNameKey { get; set; }
        /// <summary>
        /// 文件名称value
        /// </summary>
        public string FileNameValue { get; set; }
        /// <summary>
        /// 编码格式
        /// </summary>
        public Encoding Encoding { get; set; }
        /// <summary>
        /// 上传文件的流
        /// </summary>
        public Stream UploadStream { get; set; }
        /// <summary>
        /// 上传文件 携带的参数集合
        /// </summary>
        public IDictionary<string, string> PostParameters { get; set; }

*
*
*、直接调用

using (FileStream fs = new FileStream(@"C:\\test.zip", FileMode.Open, FileAccess.Read))
    Dictionary<string, string> postParameter = new Dictionary<string, string>();
    postParameter.Add("name", "heshang");
    postParameter.Add("param", "1 2 3");
    string result = HttpUploadClient.Execute(new UploadParameterType
        Url = url,
        UploadStream = fs,
        FileNameValue = "test.zip",
        PostParameters = postParameter
public IHttpActionResult Post()
    HttpPostedFile file = HttpContext.Current.Request.Files[0];
    string pyPath = HttpContext.Current.Request["name"];
    string Params = HttpContext.Current.Request["params"];
    file.SaveAs("C:\\test.zip");
    return Ok("");

*
*
*
*
*

这个小程序参考了另一位博友的代码,做了稍许调整,创建的两个Handler程序,一个上传的ashx,一个接收的ashx 上传文件代码 public void ProcessRequest(HttpContext context) //参考http://www.cnblogs.com/greenerycn/archive/2010/05/15/csharp_http_post.htm //form - data格式发送Post请求 Dictionary<string, string> dic = new Dictionary<string, string>(); dic.Add("resp_type", "1"); dic.Add("upload_type", "1"); dic.Add("img_url", "http://www.jnqian using System.Net.Security; using System.Security.Cryptography.X509Certificates; using Newtonsoft.Json; using System.IO; using System.Net; private static readonly string DefaultUserAgent = "Mozilla/5.0 (Windows NT 6.1; Win64;. var res = ""; HttpClient _httpClient = new HttpClient(); var postContent = new MultipartFormDataContent(); string boundary = string.Form...