[转]WebApi 后端文件传输至远程服务器

/*

功能说明：微信退款需要有数字证书，而我们公司是做小程序平台的，会帮商家自动退款，所以会要求商家把微信证书上传至我们服务器，以便

微信退款。

使用HttpPostedFile 接受前端上传的文件，再使用

*/

#region 证书上传 UploadCertificate

/// <summary>

/// 证书上传

/// </summary>

/// <returns></returns>

[HttpPost]

public IHttpActionResult UploadCertificate()

{

//此字段代表商家证书存储的文件夹

string enterpriseId = "test";

OperationResult response = new OperationResult

{

Code = OperationResultType.IllegalOperation,

Message = "不是有效的p12证书文件"

};

try

{

HttpFileCollection filelist = HttpContext.Current.Request.Files;

if (filelist != null && filelist.Count > 0)

{

HttpPostedFile file = filelist[0];

//文件名

string fileName = file.FileName;

if (string.IsNullOrWhiteSpace(fileName) || !fileName.Contains("."))

{

return Json(response);

}

var fileNameSplit = fileName.Trim(new[] { '"' }).Split('.');

//文件后缀名

string fileExName = fileNameSplit[fileNameSplit.Length - 1];

if (!fileExName.Equals("p12"))

{

return Json(response);

}

//上传文件至远程服务器

string res = PostResponse($"url",new HttpPostedFile[] { file });

if (!string.IsNullOrWhiteSpace(res))

{

return Json(JsonUtility.DeserializeObject<OperationResult>(res));

}

}

}

catch (Exception ex)

{

LogHelper.Error("UploadCertificate-error", ex);

}

return Json(response);

}

#endregion

#region 使用WebRequest构建多媒体文件上传远程服务器 PostResponse

/// <summary>

/// 发起httpPost 请求，可以上传文件

/// </summary>

/// <param name="url">请求的地址</param>

/// <param name="files">文件</param>

/// <returns></returns>

public static string PostResponse(string url, HttpPostedFile[] files)

{

string boundary = "----------------------------" + DateTime.Now.Ticks.ToString("x");

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);

request.ContentType = "multipart/form-data; boundary=" + boundary;

request.Method = "POST";

request.KeepAlive = true;

//request.Credentials = CredentialCache.DefaultCredentials;

request.Expect = "";

MemoryStream stream = new MemoryStream();

byte[] line = Encoding.ASCII.GetBytes("--" + boundary + "\r\n");

byte[] enterER = Encoding.ASCII.GetBytes("\r\n");

////提交文件

if (files != null)

{

string fformat = "Content-Disposition:form-data; name=\"file\";filename=\"{0}\"\r\nContent-Type:{1}\r\n\r\n";

foreach (HttpPostedFile file in files)

{

//#region HttpPostedFile.InputStream=>byte[]

//Stream inputStream = file.InputStream;//new MemoryStream();

//byte[] bytes = new byte[stream.Length];

//#endregion

var fileStream = file.InputStream;

var buffer = new byte[1024];

int bytesRead; // =0

stream.Write(line, 0, line.Length); //项目分隔符

string s = string.Format(fformat, file.FileName, file.ContentType);

byte[] data = Encoding.UTF8.GetBytes(s);

stream.Write(data, 0, data.Length);

//stream.Write(bytes, 0, bytes.Length);//文件内容

while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0)

{

stream.Write(buffer, 0, bytesRead);

}

stream.Write(enterER, 0, enterER.Length); //添加\r\n

}

}

byte[] foot_data = Encoding.UTF8.GetBytes("--" + boundary + "--\r\n"); //项目最后的分隔符字符串需要带上--

stream.Write(foot_data, 0, foot_data.Length);

request.ContentLength = stream.Length;

Stream requestStream = request.GetRequestStream(); //写入请求数据

stream.Position = 0L;

stream.CopyTo(requestStream); //

stream.Close();

requestStream.Close();

try

{

#region

HttpWebResponse response = null;

try

{

response = (HttpWebResponse)request.GetResponse();

}

catch (WebException ex)

{

response = (HttpWebResponse)ex.Response;

}

#endregion

//HttpWebResponse response = (HttpWebResponse)request.GetResponse();

Stream streamIn = response.GetResponseStream();

StreamReader reader = new StreamReader(streamIn);

string result = reader.ReadToEnd();

reader.Close();

streamIn.Close();

response.Close();

return result;

}

catch (Exception ex)

{

throw ex;

}

#endregion