C# HttpWebRequest 后台调用接口上传大文件以及其他参数

直接上代码，包各位看客能用！！！

1.首先请求参数的封装

/// <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; }
    }

　　2.HttpWebRequest 封装

/// <summary>
    /// Http上传文件类 - HttpWebRequest封装
    /// </summary>
    public class HttpUploadClient
    {
        /// <summary>
        /// 上传执行 方法
        /// </summary>
        /// <param name="parameter">上传文件请求参数</param>
        public static string Execute(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<string, string> 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);
                    }
                }
                // 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();
                memoryStream.Close();
                GC.Collect();
                // 8.HttpWebRequest 组装
                HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(new Uri(parameter.Url, UriKind.RelativeOrAbsolute));
                webRequest.AllowWriteStreamBuffering = false;
                webRequest.Method = "POST";
                webRequest.Timeout = 1800000;
                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;
                    }
                }
            }
        }
        /// <summary>
        /// 上传执行 方法
        /// </summary>
        /// <param name="parameter">上传文件请求参数</param>
        public static string Execute2(UploadParameterType parameter)
        {
            // 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);
            byte[] postBytes = new byte[] { };
            using (MemoryStream memoryStream = new MemoryStream())
            {
                // 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<string, string> 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);
                    }
                }
                // 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.组装结束分界线数据体 到内存流中
                //memoryStream.Write(endBoundaryBytes, 0, endBoundaryBytes.Length);
                // 6.获取二进制数据
                postBytes = memoryStream.ToArray();
            }
            // 7.HttpWebRequest 组装
            HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(new Uri(parameter.Url, UriKind.RelativeOrAbsolute));
            //对发送的数据不使用缓存【重要、关键】
            webRequest.AllowWriteStreamBuffering = false;
            webRequest.Method = "POST";
            webRequest.Timeout = 1800000;
            webRequest.ContentType = string.Format("multipart/form-data; boundary={0}", boundary);
            webRequest.ContentLength = postBytes.Length + parameter.UploadStream.Length+endBoundaryBytes.Length;
            if (Regex.IsMatch(parameter.Url, "^https://"))
            {
                ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls;
                ServicePointManager.ServerCertificateValidationCallback = CheckValidationResult;
            }
            // 8.组装文件流
            byte[] buffer = new byte[1024 * 1024 * 1];
            int size = parameter.UploadStream.Read(buffer, 0, buffer.Length);
            Stream requestStream = webRequest.GetRequestStream();
            requestStream.Write(postBytes, 0, postBytes.Length);
            while (size > 0)
            {
                requestStream.Write(buffer, 0, size);
                size = parameter.UploadStream.Read(buffer, 0, buffer.Length);
            }
            requestStream.Write(endBoundaryBytes, 0, endBoundaryBytes.Length);
            requestStream.Close();
            // 9.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;
        }

    }

　　HttpUploadClient类中两个Execute2，参考网上，大都用第一个，如果上传小文件没问题，要是比较大（百兆以上）就会内存溢出，然后就用流方式。思路是一样的

3.调用示例：

            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
                });
            }

　　4.接口服务后台接受请求时：

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("");
        }

　　5.完美解决大文件上传