主体

            Dictionary<string, object> postData = new Dictionary<string, object>();           string fileFullPath = this.imgFullPath;if (!File.Exists(fileFullPath)){Message(Error, "file not exist: " + fileFullPath);goto EndGetPost;}// 先定义一个byte数组// 将指定的文件数据读取到 数组中byte[] bFile = null;// path是文件的路径using (FileStream fs = new FileStream(fileFullPath, FileMode.Open)){// 定义这个byte[]数组的长度 为文件的lengthbFile = new byte[fs.Length];// 把fs文件读入到arrFile数组中，0是指偏移量，从0开始读，arrFile.length是指需要读的长度，也就是整个文件的长度fs.Read(bFile, 0, bFile.Length);}postData.Add("file", new FileParameter(bFile, fileFullPath, "image/jpg"));//--------------------------------------// Create request and receive responsestring postURL = this.url;string userAgent = "Mozilla/5.0 (Windows NT 10.0;Win64;x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/31.0.1650.57 Safari/537.36";HttpWebResponse webResponse = FormUpload.MultipartFormDataPost(postURL, userAgent, postParameters);// Process responseStreamReader responseReader = new StreamReader(webResponse.GetResponseStream());fullResponse = responseReader.ReadToEnd();responseReader.Close();webResponse.Close();

类

 /// <summary>/// 表单数据项./// </summary>public static class FormUpload{private static readonly Encoding ENCODING = Encoding.UTF8;/// <summary>/// MultipartFormDataPost./// </summary>/// <param name="postUrl">.</param>/// <param name="userAgent">string.</param>/// <param name="postParameters">send.</param>/// <returns>HttpWebResponse.</returns>public static HttpWebResponse MultipartFormDataPost(string postUrl, string userAgent, Dictionary<string, object> postParameters){string formDataBoundary = string.Format("----------{0:N}", Guid.NewGuid());string contentType = "multipart/form-data; boundary=" + formDataBoundary;byte[] formData = GetMultipartFormData(postParameters, formDataBoundary);return PostForm(postUrl, userAgent, contentType, formData);}/// <summary>/// send to api./// </summary>/// <param name="postUrl">url.</param>/// <param name="userAgent">string agent.</param>/// <param name="contentType">send type.</param>/// <param name="formData">type.</param>/// <returns>HttpWebResponse.</returns>private static HttpWebResponse PostForm(string postUrl, string userAgent, string contentType, byte[] formData){// use https or http// HttpWebRequest request = WebRequest.Create(postUrl) as HttpWebRequest;HttpWebRequest request = null;if (postUrl.StartsWith("https", StringComparison.OrdinalIgnoreCase)){Message(Warning, "use https:-------");request = WebRequest.Create(postUrl) as HttpWebRequest;ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);request.ProtocolVersion = HttpVersion.Version11;// 这里设置了协议类型。// SecurityProtocolType.Tls1.2;ServicePointManager.SecurityProtocol = (SecurityProtocolType)3072;request.KeepAlive = false;ServicePointManager.CheckCertificateRevocationList = true;ServicePointManager.DefaultConnectionLimit = 100;ServicePointManager.Expect100Continue = false;}else{Message(Warning, "use http default");request = (HttpWebRequest)WebRequest.Create(postUrl);}// start -------if (request == null){throw new NullReferenceException("request is not a http request");}// Set up the request properties.request.Method = "POST";request.ContentType = contentType;request.UserAgent = userAgent;request.CookieContainer = new CookieContainer();request.ContentLength = formData.Length;request.Accept = "application/json";// You could add authentication here as well if needed:// request.PreAuthenticate = true;// request.AuthenticationLevel = System.Net.Security.AuthenticationLevel.MutualAuthRequested;// request.Headers.Add("Authorization", "Basic " + Convert.ToBase64String(System.Text.Encoding.Default.GetBytes("username" + ":" + "password")));// Send the form data to the request.using (Stream requestStream = request.GetRequestStream()){requestStream.Write(formData, 0, formData.Length);requestStream.Close();}return request.GetResponse() as HttpWebResponse;}private static byte[] GetMultipartFormData(Dictionary<string, object> postParameters, string boundary){Stream formDataStream = new System.IO.MemoryStream();bool needsCLRF = false;foreach (var param in postParameters){// Thanks to feedback from commenters, add a CRLF to allow multiple parameters to be added.// Skip it on the first parameter, add it to subsequent parameters.if (needsCLRF){formDataStream.Write(ENCODING.GetBytes("\r\n"), 0, ENCODING.GetByteCount("\r\n"));}needsCLRF = true;if (param.Value is FileParameter){FileParameter fileToUpload = (FileParameter)param.Value;// Add just the first part of this param, since we will write the file data directly to the Streamstring header = string.Format("--{0}\r\nContent-Disposition: form-data; name=\"{1}\"; filename=\"{2}\"\r\nContent-Type: {3}\r\n\r\n",boundary,param.Key,fileToUpload.FileName ?? param.Key,fileToUpload.ContentType ?? "application/octet-stream");formDataStream.Write(ENCODING.GetBytes(header), 0, ENCODING.GetByteCount(header));// Write the file data directly to the Stream, rather than serializing it to a string.formDataStream.Write(fileToUpload.File, 0, fileToUpload.File.Length);}else{string postData = string.Format("--{0}\r\nContent-Disposition: form-data; name=\"{1}\"\r\n\r\n{2}",boundary,param.Key,param.Value);formDataStream.Write(ENCODING.GetBytes(postData), 0, ENCODING.GetByteCount(postData));}}// Add the end of the request.  Start with a newlinestring footer = "\r\n--" + boundary + "--\r\n";formDataStream.Write(ENCODING.GetBytes(footer), 0, ENCODING.GetByteCount(footer));// Dump the Stream into a byte[]formDataStream.Position = 0;byte[] formData = new byte[formDataStream.Length];formDataStream.Read(formData, 0, formData.Length);formDataStream.Close();return formData;}/// <summary>/// CheckValidationResult./// </summary>/// <param name="sender">sender.</param>/// <param name="certificate">certificate.</param>/// <param name="chain">chain.</param>/// <param name="errors">errors.</param>/// <returns>true.</returns>private static bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors){// 总是接受return true;}}/// <summary>/// FileParameter./// </summary>public class FileParameter{/// <summary>/// Initializes a new instance of the <see cref="FileParameter"/> class./// FileParameter./// </summary>/// <param name="file">file.</param>/// <param name="filename">filename.</param>/// <param name="contenttype">contenttype.</param>public FileParameter(byte[] file, string filename, string contenttype){this.File = file;this.FileName = filename;this.ContentType = contenttype;}/// <summary>/// Gets or sets File./// </summary>public byte[] File { get; set; }/// <summary>/// Gets or sets FileName./// </summary>public string FileName { get; set; }/// <summary>/// Gets or sets ContentType./// </summary>public string ContentType { get; set; }}