在使用 HttpWebRequest Post数据时候返回 400错误

远程服务器返回错误:(400)错误的请求

///<summary>
///发起httpPost请求，可以上传文件
///</summary>
///<paramname="url">请求的地址</param>
///<paramname="files">文件</param>
///<paramname="input">表单数据</param>
///<paramname="endoding">编码</param>
///<returns></returns>
publicstaticstringPostResponse(stringurl,UpLoadFile[]files,Dictionary<string,string>input,Encodingendoding)
{

stringboundary="----------------------------"+DateTime.Now.Ticks.ToString("x");
HttpWebRequestrequest=(HttpWebRequest)WebRequest.Create(url);
request.ContentType="multipart/form-data;boundary="+boundary;
request.Method="POST";
request.KeepAlive=true;
//request.Credentials=CredentialCache.DefaultCredentials;
request.Expect="";

MemoryStreamstream=newMemoryStream();

byte[]line=Encoding.ASCII.GetBytes("--"+boundary+"\r\n");
byte[]enterER=Encoding.ASCII.GetBytes("\r\n");
////提交文件
if(files!=null)
{
stringfformat="Content-Disposition:form-data;name=\"{0}\";filename=\"{1}\"\r\nContent-Type:{2}\r\n\r\n";
foreach(UpLoadFilefileinfiles)
{

stream.Write(line,0,line.Length);//项目分隔符
strings=string.Format(fformat,file.Name,file.FileName,file.Content_Type);
byte[]data=Encoding.UTF8.GetBytes(s);
stream.Write(data,0,data.Length);
stream.Write(file.Data,0,file.Data.Length);
stream.Write(enterER,0,enterER.Length);//添加\r\n
}
}

//提交文本字段
if(input!=null)
{
stringformat="--"+boundary+"\r\nContent-Disposition:form-data;name=\"{0}\"\r\n\r\n{1}\r\n";//自带项目分隔符
foreach(stringkeyininput.Keys)
{
strings=string.Format(format,key,input[key]);
byte[]data=Encoding.UTF8.GetBytes(s);
stream.Write(data,0,data.Length);
}

}

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;
StreamrequestStream=request.GetRequestStream();//写入请求数据
stream.Position=0L;
stream.CopyTo(requestStream);//
stream.Close();

requestStream.Close();

try
{

HttpWebResponseresponse;
try
{
response=(HttpWebResponse)request.GetResponse();

try
{
using(varresponseStream=response.GetResponseStream())
using(varmstream=newMemoryStream())
{
responseStream.CopyTo(mstream);
stringmessage=endoding.GetString(mstream.ToArray());
returnmessage;
}
}
catch(Exceptionex)
{
throwex;
}
}
catch(WebExceptionex)
{
//response=(HttpWebResponse)ex.Response;

//if(response.StatusCode==HttpStatusCode.BadRequest)
//{
//using(Streamdata=response.GetResponseStream())
//{
//using(StreamReaderreader=newStreamReader(data))
//{
//stringtext=reader.ReadToEnd();
//Console.WriteLine(text);
//}
//}
//}

throwex;
}

}
catch(Exceptionex)
{
throwex;
}
}

------WebKitFormBoundarydhy7IYZyMgmp2cLv--
实际上他是"--"+boundary+"--\r\n"，可以参考上文中代码54行

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读者如果觉得我讲的比较迷糊可以参考下下面这篇博文进行对比学习http://blog.csdn.net/five3/article/details/7181521
听说Post传输数据有好几种形式哦，后续继续分析，欢迎拍砖