我无法读取文件名以及来自客户端的其他值。我使用HttpWebRequest将多部分数据发送到服务器。我的客户端代码如下所示：
public string upload(string file, string url)
{
HttpWebRequest requestToServer = (HttpWebRequest)
WebRequest.Create(url);
// Define a boundary string
string boundaryString = "----";
// Turn off the buffering of data to be written, to prevent
// OutOfMemoryException when sending data
requestToServer.AllowWriteStreamBuffering = false;
// Specify that request is a HTTP post
requestToServer.Method = WebRequestMethods.Http.Post;
// Specify that the content type is a multipart request
requestToServer.ContentType
= "multipart/form-data; boundary=" + boundaryString;
// Turn off keep alive
requestToServer.KeepAlive = false;
ASCIIEncoding ascii = new ASCIIEncoding();
string boundaryStringLine = "\r\n--" + boundaryString + "\r\n";
byte[] boundaryStringLineBytes = ascii.GetBytes(boundaryStringLine);
string lastBoundaryStringLine = "\r\n--" + boundaryString + "--\r\n";
byte[] lastBoundaryStringLineBytes = ascii.GetBytes(lastBoundaryStringLine);
NameValueCollection nvc = new NameValueCollection();
nvc.Add("id", "TTR");
// Get the byte array of the myFileDescription content disposition
string myFileDescriptionContentDisposition = Java.Lang.String.Format(
"Content-Disposition: form-data; name=\"{0}\"\r\n\r\n{1}",
"myFileDescription",
"A sample file description");
byte[] myFileDescriptionContentDispositionBytes
= ascii.GetBytes(myFileDescriptionContentDisposition);
string fileUrl = file;
// Get the byte array of the string part of the myFile content
// disposition
string myFileContentDisposition = Java.Lang.String.Format(
"Content-Disposition: form-data;name=\"{0}\"; "
+ "filename=\"{1}\"\r\nContent-Type: {2}\r\n\r\n",
"myFile", Path.GetFileName(fileUrl), Path.GetExtension(fileUrl));
byte[] myFileContentDispositionBytes =
ascii.GetBytes(myFileContentDisposition);
var name = Path.GetFileName(fileUrl);
FileInfo fileInfo = new FileInfo(fileUrl);
// Calculate the total size of the HTTP request
long totalRequestBodySize = boundaryStringLineBytes.Length * 2
+ lastBoundaryStringLineBytes.Length
+ myFileDescriptionContentDispositionBytes.Length
+ myFileContentDispositionBytes.Length
+ fileInfo.Length;
// And indicate the value as the HTTP request content length
requestToServer.ContentLength = totalRequestBodySize;
string formdataTemplate = "Content-Disposition: form-data; name=\"{0}\"\r\n\r\n{1}";
// Write the http request body directly to the server
using (Stream s = requestToServer.GetRequestStream())
{
//foreach (string key in nvc.Keys)
//{
// s.Write(boundaryStringLineBytes, 0, boundaryStringLineBytes.Length);
// string formitem = string.Format(formdataTemplate, key, nvc[key]);
// byte[] formitembytes = System.Text.Encoding.UTF8.GetBytes(formitem);
// s.Write(formitembytes, 0, formitembytes.Length);
//}
// Send the file description content disposition over to the server
s.Write(boundaryStringLineBytes, 0, boundaryStringLineBytes.Length);
s.Write(myFileDescriptionContentDispositionBytes, 0,
myFileDescriptionContentDispositionBytes.Length);
// Send the file content disposition over to the server
s.Write(boundaryStringLineBytes, 0, boundaryStringLineBytes.Length);
s.Write(myFileContentDispositionBytes, 0,
myFileContentDispositionBytes.Length);
// Send the file binaries over to the server, in 1024 bytes chunk
FileStream fileStream = new FileStream(fileUrl, FileMode.Open,
FileAccess.Read);
byte[] buffer = new byte[1024];
int bytesRead = 0;
while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0)
{
s.Write(buffer, 0, bytesRead);
} // end while
fileStream.Close();
// Send the last part of the HTTP request body
s.Write(lastBoundaryStringLineBytes, 0, lastBoundaryStringLineBytes.Length);
WebResponse response = requestToServer.GetResponse();
StreamReader responseReader = new StreamReader(response.GetResponseStream());
string replyFromServer = responseReader.ReadToEnd();
return replyFromServer;
}
}
在服务器端没有检索到客户端写入的内容处理值。在服务器端，文件名读作＆＃34; {0}＆＃34;然后将其他值读作＆＃34; {1}＆＃34;和＆＃34; {2}＆＃34;。
我的服务器端代码如下：
public async Task<HttpResponseMessage> UploadFile()
{
if (!Request.Content.IsMimeMultipartContent())
{
throw new HttpResponseException(HttpStatusCode.UnsupportedMediaType);
}
string root = HttpContext.Current.Server.MapPath("~/App_Data");
var provider = new MultipartFormDataStreamProvider(root);
var httpRequest = HttpContext.Current.Request;
var id = httpRequest.Form["{0}"];
var id2 = httpRequest.Form[0];
var s = id;
var l = id2;
// Read the form data.
await Request.Content.ReadAsMultipartAsync(provider);
// This illustrates how to get the file names.
foreach (MultipartFileData file in provider.FileData)
{
Trace.WriteLine(file.Headers.ContentDisposition.FileName);
Trace.WriteLine("Server file path: " + file.LocalFileName);
}
if (httpRequest.Files.Count > 0)
{
foreach (string file in httpRequest.Files)
{
var postedFile = httpRequest.Files[file];
var filePath = HttpContext.Current.Server.MapPath("~/" + postedFile.FileName);
postedFile.SaveAs(filePath);
// NOTE: To store in memory use postedFile.InputStream
}
return Request.CreateResponse(HttpStatusCode.Created);
}
return Request.CreateResponse(HttpStatusCode.BadRequest);
}
我已经被困在这2天了，这让我发疯了。我已经多次切碎并更改了我的代码，但每次都有不同的问题。这是我最接近使我的代码工作，除了在服务器上正确读取标题。
我将永远感谢能帮助我的人。
答案 0 :(得分：1)
您的客户端很可能就像Android应用程序一样。您在那里使用Java.Lang.String.Format，并且java格式字符串的语法与.NET格式字符串不同，因此您的{0} {1}等placesholders不会被扩展。要修复，只需使用常规的.NET String.Format。