.net后台webclient用post方式发送文件和数据

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.IO;
using System.Text;
using System.Net;

namespace BcpMobile.Handlers
{
/// <summary>
/// description：http post请求客户端
/// last-modified-date：2012-02-28
/// </summary>
public class HttpRequestClient
{
#region //字段
private ArrayList bytesArray;
private Encoding encoding = Encoding.UTF8;
private string boundary = String.Empty;
#endregion

#region //构造方法
public HttpRequestClient()
{
bytesArray = new ArrayList();
string flag = DateTime.Now.Ticks.ToString("x");
boundary = "---------------------------" + flag;
}
#endregion

#region //方法
/// <summary>
/// 合并请求数据
/// </summary>
/// <returns></returns>
private byte[] MergeContent()
{
int length = 0;
int readLength = 0;
string endBoundary = "--" + boundary + "--\r\n";
byte[] endBoundaryBytes = encoding.GetBytes(endBoundary);

bytesArray.Add(endBoundaryBytes);

foreach (byte[] b in bytesArray)
{
length += b.Length;
}

byte[] bytes = new byte[length];

foreach (byte[] b in bytesArray)
{
b.CopyTo(bytes, readLength);
readLength += b.Length;
}

return bytes;
}

/// <summary>
/// 上传
/// </summary>
/// <param name="requestUrl">请求url</param>
/// <param name="responseText">响应</param>
/// <returns></returns>
public bool Upload(String requestUrl, out String responseText)
{
WebClient webClient = new WebClient();
webClient.Headers.Add("Content-Type", "multipart/form-data; boundary=" + boundary);

byte[] responseBytes;
byte[] bytes = MergeContent();

try
{
responseBytes = webClient.UploadData(requestUrl, bytes);
responseText = System.Text.Encoding.UTF8.GetString(responseBytes);
return true;
}
catch (WebException ex)
{
Stream responseStream = ex.Response.GetResponseStream();
responseBytes = new byte[ex.Response.ContentLength];
responseStream.Read(responseBytes, 0, responseBytes.Length);
}
responseText = System.Text.Encoding.UTF8.GetString(responseBytes);
return false;
}

/// <summary>
/// 设置表单数据字段
/// </summary>
/// <param name="fieldName">字段名</param>
/// <param name="fieldValue">字段值</param>
/// <returns></returns>
public void SetFieldValue(String fieldName, String fieldValue)
{
string httpRow = "--" + boundary + "\r\nContent-Disposition: form-data; name=\"{0}\"\r\n\r\n{1}\r\n";
string httpRowData = String.Format(httpRow, fieldName, fieldValue);

bytesArray.Add(encoding.GetBytes(httpRowData));
}

/// <summary>
/// 设置表单文件数据
/// </summary>
/// <param name="fieldName">字段名</param>
/// <param name="filename">字段值</param>
/// <param name="contentType">内容内型</param>
/// <param name="fileBytes">文件字节流</param>
/// <returns></returns>
public void SetFieldValue(String fieldName, String filename, String contentType, Byte[] fileBytes)
{
string end = "\r\n";
string httpRow = "--" + boundary + "\r\nContent-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\nContent-Type: {2}\r\n\r\n";
string httpRowData = String.Format(httpRow, fieldName, filename, contentType);

byte[] headerBytes = encoding.GetBytes(httpRowData);
byte[] endBytes = encoding.GetBytes(end);
byte[] fileDataBytes = new byte[headerBytes.Length + fileBytes.Length + endBytes.Length];

headerBytes.CopyTo(fileDataBytes, 0);
fileBytes.CopyTo(fileDataBytes, headerBytes.Length);
endBytes.CopyTo(fileDataBytes, headerBytes.Length + fileBytes.Length);

bytesArray.Add(fileDataBytes);
}
#endregion
}
}

private void sendFileData(string sUrl, string pdfPathName, int member_id, string access_token, out string responseText)
{
string url = sUrl;//发送到的页面的地址
string image_path = pdfPathName;//文件的位置
FileStream fs = new FileStream(image_path, System.IO.FileMode.Open, System.IO.FileAccess.Read);

byte[] fileBytes = new byte[fs.Length];
fs.Read(fileBytes, 0, fileBytes.Length);
fs.Close();
fs.Dispose();

HttpRequestClient httpRequestClient = new HttpRequestClient();
httpRequestClient.SetFieldValue("member_id", member_id.ToString());//发送数据
httpRequestClient.SetFieldValue("access_token", access_token);//发送数据
int pos = image_path.LastIndexOf("\\");
string fileName = image_path.Substring(pos + 1);
httpRequestClient.SetFieldValue("key", fileName, "application/octet-stream", fileBytes);
bool uploaded = httpRequestClient.Upload(url, out responseText);
}

/// <summary>
/// post发送数据
/// </summary>
///  <param name="url">接收地址</param>
/// <param name="postString">拼接Post字符串"arg1=a&arg2=b"</param>
/// <returns></returns>
public static string HttpUploadData(string url, string postString)
{
byte[] postData = Encoding.UTF8.GetBytes(postString);//编码，尤其是汉字，事先要看下抓取网页的编码方式
WebClient webClient = new WebClient();
webClient.Headers.Add("Content-Type", "application/x-www-form-urlencoded");//采取POST方式必须加的header，如果改为GET方式的话就去掉这句话即可
byte[] responseData = webClient.UploadData(url, "POST", postData);//得到返回字符流
return   Encoding.UTF8.GetString(responseData);//解码
}