C# 模拟上传图片

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.IO;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
Dictionary<string, string> inputDic=new Dictionary<string,string>();
inputDic.Add("username","westfruit");
inputDic.Add("password","");
PostFile("http://avatar.csdn.net/0/1/1/1_zfrong.jpg", "http://www.westfruit.com/news/uppic.asp?strAction=shangchuan", @"D:\1.jpg", "application/octet-stream", inputDic);
} #region 下载文件并上传到指定页面
/**
* 如果要在客户端向服务器上传文件，我们就必须模拟一个POST multipart/form-data类型的请求
* Content-Type必须是multipart/form-data。
* 以multipart/form-data编码的POST请求格式与application/x-www-form-urlencoded完全不同
* multipart/form-data需要首先在HTTP请求头设置一个分隔符,例如7d4a6d158c9：
* 我们模拟的提交要设定 content-type不同于非含附件的post时候的content-type
* 这里需要： ("Content-Type", "multipart/form-data; boundary=ABCD");
* 然后，将每个字段用“--7d4a6d158c9”分隔，最后一个“--7d4a6d158c9--”表示结束。
* 例如，要上传一个title字段"Today"和一个文件C:\1.txt，HTTP正文如下：
*
* --7d4a6d158c9
* Content-Disposition: form-data; name="title"
* \r\n\r\n
* Today
* --7d4a6d158c9
* Content-Disposition: form-data; name="1.txt"; filename="C:\1.txt"
* Content-Type: text/plain
* 如果是图片Content-Type: application/octet-stream
* \r\n\r\n
* <这里是1.txt文件的内容>
* --7d4a6d158c9
* \r\n
* 请注意，每一行都必须以\r\n结束value前面必须有2个\r\n，包括最后一行。
*/
/// <summary>
/// 下载文件上传到指定地址
/// </summary>
/// <param name="getUrl">文件下载地址</param>
/// <param name="postUrl">文件上传地址</param>
/// <param name="fileName">file控件名称</param>
/// <param name="fileType">上传文件类型</param>
/// <param name="inputParamter">其他表单元素</param>
public static void PostFile(string getUrl, string postUrl, string fileName, string fileType, Dictionary<string, string> inputDic)
{ CredentialCache cache = new CredentialCache();//创建缓存容器
cache.Add(new Uri("http://www.westfruit.com/"), "Basic", new NetworkCredential("westfruit", ""));
CookieContainer cookies = new CookieContainer();//创建cookie容器
MemoryStream fileStream = GetFileStream(getUrl);//下载文件返回内存流
// cast the WebRequest to a HttpWebRequest since we're using HTTPS
string boundary = "----------" + DateTime.Now.Ticks.ToString("x");//元素分割标记
HttpWebRequest httpWebRequest2 = (HttpWebRequest)WebRequest.Create(postUrl);
httpWebRequest2.Credentials = cache;
httpWebRequest2.CookieContainer = cookies;
httpWebRequest2.ContentType = "multipart/form-data; boundary=" + boundary;//其他地方的boundary要比这里多--
httpWebRequest2.Method = "POST";//Post请求方式
// Build up the post message 拼接创建表单内容
StringBuilder sb = new StringBuilder();
//拼接非文件表单控件
//遍历字典取出表单普通空间的健和值
foreach (KeyValuePair<string, string> dicItem in inputDic)
{
sb.Append("--" + boundary);
sb.Append("\r\n");
sb.Append("Content-Disposition: form-data; name=\"" + dicItem.Key + "\"");
sb.Append("\r\n");
sb.Append("\r\n");
sb.Append(dicItem.Value);//value前面必须有2个换行
sb.Append("\r\n");
}
//拼接文件控件
sb.Append("--"+boundary);
sb.Append("\r\n");
sb.Append("Content-Disposition: form-data; name=\"file1\"; filename=\"C:\\upload" + Path.GetFileName(fileName) + "\"");
sb.Append("\r\n");
sb.Append("Content-Type: application/octet-stream");
sb.Append("\r\n");
sb.Append("\r\n");//value前面必须有2个换行
byte[] postHeaderBytes = Encoding.UTF8.GetBytes(sb.ToString());
// Build the trailing boundary string as a byte array 创建结束标记
// ensuring the boundary appears on a line by itself
byte[] boundaryBytes = Encoding.ASCII.GetBytes("\r\n--" + boundary + "\r\n");
//http请求总长度
httpWebRequest2.ContentLength = postHeaderBytes.Length + fileStream.Length + boundaryBytes.Length;
Stream requestStream = httpWebRequest2.GetRequestStream(); //定义一个http请求流
// Write out our post header 将开始标记写入流
requestStream.Write(postHeaderBytes, , postHeaderBytes.Length);
// Write out the file contents 将附件写入流,最大4M
byte[] buffer = new Byte[checked((uint)Math.Min(, (int)fileStream.Length))];
int bytesRead = ;
while ((bytesRead = fileStream.Read(buffer, , buffer.Length)) != )
requestStream.Write(buffer, , bytesRead);
fileStream.Dispose();
// Write out the trailing boundary 将结束标记写入流
requestStream.Write(boundaryBytes, , boundaryBytes.Length);
//Send http request back WebResponse 发送http请求
WebResponse webResponse2 = httpWebRequest2.GetResponse();
//从WebResponse中解析出html代码开始
Stream htmlStream = webResponse2.GetResponseStream();
string HTML = GetHtml(htmlStream, "UTF-8");
htmlStream.Dispose();
//从WebResponse中解析出html代码结束
}
#endregion
#region 下载文件
/// <summary>
/// 从互联网下载文件
/// </summary>
/// <param name="getUrl">文件地址</param>
/// <returns>内存流</returns>
public static MemoryStream GetFileStream(string getUrl)
{
MemoryStream fileStream;//定义一个内存流保存接收到的文件流
HttpWebRequest httpWebRequest1 = (HttpWebRequest)WebRequest.Create(getUrl);
WebResponse webResponse1 = httpWebRequest1.GetResponse();
byte[] buffer1 = new byte[];//定义一个4M大小的数字
Stream stream1 = webResponse1.GetResponseStream();//定义一个流接受html返回的文件流
fileStream = new MemoryStream();//stream1不支持查找操作所以将其转入内存流
int l;
do
{
l = stream1.Read(buffer1, , buffer1.Length);
if (l > )
{
fileStream.Write(buffer1, , l);//将文件流按字节写入内存流
}
}
while (l > );
stream1.Close();
fileStream.Position = ;
return fileStream;
}
#endregion
#region 解析html代码
/// <summary>
/// 从html流中解析出html代码
/// </summary>
/// <param name="htmlStream">html流</param>
/// <param name="Encoding">编码格式</param>
/// <returns>html</returns>
public static string GetHtml(Stream htmlStream, string Encoding)
{
StreamReader objReader = new StreamReader(htmlStream, System.Text.Encoding.GetEncoding(Encoding));
string HTML = "";
string sLine = "";
int i = ;
while (sLine != null)
{
i++;
sLine = objReader.ReadLine();
if (sLine != null)
HTML += sLine;
}
HTML = HTML.Replace("<", "<");
HTML = HTML.Replace(">", ">");
objReader.Dispose();
return HTML;
}
#endregion
}
}