使用HttpWebRequest POST图片等文件，带参数

代码如下：

public   string  HttpUploadFile( string  url,  string  file,  string  paramName,  string  contentType, NameValueCollection nvc)
{
     string  result  =   string .Empty;
     string  boundary  =   " --------------------------- "   +  DateTime.Now.Ticks.ToString( " x " );
     byte [] boundarybytes  =  System.Text.Encoding.ASCII.GetBytes( " \r\n-- "   +  boundary  +   " \r\n " );

    HttpWebRequest wr  =  (HttpWebRequest)WebRequest.Create(url);
    wr.ContentType  =   " multipart/form-data; boundary= "   +  boundary;
    wr.Method  =   " POST " ;
    wr.KeepAlive  =   true ;
    wr.Credentials  =  System.Net.CredentialCache.DefaultCredentials;

    Stream rs  =  wr.GetRequestStream();

     string  formdataTemplate  =   " Content-Disposition: form-data; name=\"{0}\"\r\n\r\n{1} " ;
     foreach  ( string  key  in  nvc.Keys)
    {
        rs.Write(boundarybytes,  0 , boundarybytes.Length);
         string  formitem  =   string .Format(formdataTemplate, key, nvc[key]);
         byte [] formitembytes  =  System.Text.Encoding.UTF8.GetBytes(formitem);
        rs.Write(formitembytes,  0 , formitembytes.Length);
    }
    rs.Write(boundarybytes,  0 , boundarybytes.Length);

     string  headerTemplate  =   " Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\nContent-Type: {2}\r\n\r\n " ;
     string  header  =   string .Format(headerTemplate, paramName, file, contentType);
     byte [] headerbytes  =  System.Text.Encoding.UTF8.GetBytes(header);
    rs.Write(headerbytes,  0 , headerbytes.Length);

    FileStream fileStream  =   new  FileStream(file, FileMode.Open, FileAccess.Read);
     byte [] buffer  =   new   byte [ 4096 ];
     int  bytesRead  =   0 ;
     while  ((bytesRead  =  fileStream.Read(buffer,  0 , buffer.Length))  !=   0 )
    {
        rs.Write(buffer,  0 , bytesRead);
    }
    fileStream.Close();

     byte [] trailer  =  System.Text.Encoding.ASCII.GetBytes( " \r\n-- "   +  boundary  +   " --\r\n " );
    rs.Write(trailer,  0 , trailer.Length);
    rs.Close();

    WebResponse wresp  =   null ;
     try
    {
        wresp  =  wr.GetResponse();
        Stream stream2  =  wresp.GetResponseStream();
        StreamReader reader2  =   new  StreamReader(stream2);

        result  =  reader2.ReadToEnd();
    }
     catch  (Exception ex)
    {
         if  (wresp  !=   null )
        {
            wresp.Close();
            wresp  =   null ;
        }
    }
     finally
    {
        wr  =   null ;
    }

     return  result;
}

调用：

// 调用实例
NameValueCollection nvc  =   new  NameValueCollection();
nvc.Add( " id " ,  " TTR " );
nvc.Add( " btn-submit-photo " ,  " Upload " );
HttpUploadFile( " http://your.server.com/upload " , 
@" C:\test\test.jpg " ,  " file " ,  " image/jpeg " , nvc);

 

参考:
http://stackoverflow.com/questions/566462/upload-files-with-httpwebrequest-multipart-form-data/1924810#1924810

转自：http://www.cnblogs.com/94cool/archive/2011/03/05/1971873.html