表单提交协议规定:
要先将 HTTP 要求的 Content-Type 设为 multipart/form-data,而且要设定一个 boundary 参数,
这个参数是由应用程序自行产生,它会用来识别每一份资料的边界 (boundary),
用以产生多重信息部份 (message part)。
而 HTTP 服务器可以抓取 HTTP POST 的信息,
基本内容:
1. 每个信息部份都要用 --[BOUNDARY_NAME] 来包装,以分隔出信息的每个部份,而最后要再加上一个 --[BOUNDARY_NAME] 来表示结束。
2. 每个信息部份都要有一个 Content-Disposition: form-data; name="",而 name 设定的就是 HTTP POST 的键值 (key)。
3. 声明区和值区中间要隔两个新行符号(\r\n)。
4. 中间可以夹入二进制资料,但二进制资料必须要格式化为二进制字符串。
5. 若要设定不同信息段的资料型别 (Content-Type),则要在信息段内的声明区设定。
两个form内容模板
boundary = "----" + DateTime.Now.Ticks.ToString("x");//程序生成
1.文本内容
"\r\n--" + boundary +
"\r\nContent-Disposition: form-data; name=\"键\"; filename=\"文件名\"" +
"\r\nContent-Type: application/octet-stream" +
"\r\n\r\n";
2.文件内容
"\r\n--" + boundary +
"\r\nContent-Disposition: form-data; name=\"键\"" +
"\r\n\r\n内容";
代码
1.表示一个表单项的对象
- public class FormItemModel
- {
-
-
-
- public string Key { set; get; }
-
-
-
- public string Value { set; get; }
-
-
-
- public bool IsFile
- {
- get
- {
- if (FileContent==null || FileContent.Length == 0)
- return false;
-
- if (FileContent != null && FileContent.Length > 0 && string.IsNullOrWhiteSpace(FileName))
- throw new Exception("上传文件时 FileName 属性值不能为空");
- return true;
- }
- }
-
-
-
- public string FileName { set; get; }
-
-
-
- public Stream FileContent { set; get; }
- }
2.提交表单主逻辑实现
- public static string PostForm(string url, List<FormItemModel> formItems, CookieContainer cookieContainer = null, string refererUrl = null, Encoding encoding = null,int timeOut = 20000)
- {
- HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
- #region 初始化请求对象
- request.Method = "POST";
- request.Timeout = timeOut;
- request.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8";
- request.KeepAlive = true;
- request.UserAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/31.0.1650.57 Safari/537.36";
- if (!string.IsNullOrEmpty(refererUrl))
- request.Referer = refererUrl;
- if (cookieContainer != null)
- request.CookieContainer = cookieContainer;
- #endregion
-
- string boundary = "----" + DateTime.Now.Ticks.ToString("x");
- request.ContentType = string.Format("multipart/form-data; boundary={0}", boundary);
-
- var postStream = new MemoryStream();
- #region 处理Form表单请求内容
-
- var formUploadFile = formItems != null && formItems.Count > 0;
- if (formUploadFile)
- {
-
- string fileFormdataTemplate =
- "\r\n--" + boundary +
- "\r\nContent-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"" +
- "\r\nContent-Type: application/octet-stream" +
- "\r\n\r\n";
-
- string dataFormdataTemplate =
- "\r\n--" + boundary +
- "\r\nContent-Disposition: form-data; name=\"{0}\"" +
- "\r\n\r\n{1}";
- foreach (var item in formItems)
- {
- string formdata = null;
- if (item.IsFile)
- {
-
- formdata = string.Format(
- fileFormdataTemplate,
- item.Key,
- item.FileName);
- }
- else
- {
-
- formdata = string.Format(
- dataFormdataTemplate,
- item.Key,
- item.Value);
- }
-
-
- byte[] formdataBytes = null;
-
- if (postStream.Length == 0)
- formdataBytes = Encoding.UTF8.GetBytes(formdata.Substring(2, formdata.Length - 2));
- else
- formdataBytes = Encoding.UTF8.GetBytes(formdata);
- postStream.Write(formdataBytes, 0, formdataBytes.Length);
-
-
- if (item.FileContent != null && item.FileContent.Length>0)
- {
- using (var stream = item.FileContent)
- {
- byte[] buffer = new byte[1024];
- int bytesRead = 0;
- while ((bytesRead = stream.Read(buffer, 0, buffer.Length)) != 0)
- {
- postStream.Write(buffer, 0, bytesRead);
- }
- }
- }
- }
-
- var footer = Encoding.UTF8.GetBytes("\r\n--" + boundary + "--\r\n");
- postStream.Write(footer, 0, footer.Length);
-
- }
- else
- {
- request.ContentType = "application/x-www-form-urlencoded";
- }
- #endregion
-
- request.ContentLength = postStream.Length;
-
- #region 输入二进制流
- if (postStream != null)
- {
- postStream.Position = 0;
-
- Stream requestStream = request.GetRequestStream();
-
- byte[] buffer = new byte[1024];
- int bytesRead = 0;
- while ((bytesRead = postStream.Read(buffer, 0, buffer.Length)) != 0)
- {
- requestStream.Write(buffer, 0, bytesRead);
- }
-
-
-
-
-
- postStream.Close();
- }
- #endregion
-
- HttpWebResponse response = (HttpWebResponse)request.GetResponse();
- if (cookieContainer != null)
- {
- response.Cookies = cookieContainer.GetCookies(response.ResponseUri);
- }
-
- using (Stream responseStream = response.GetResponseStream())
- {
- using (StreamReader myStreamReader = new StreamReader(responseStream, encoding ?? Encoding.UTF8))
- {
- string retString = myStreamReader.ReadToEnd();
- return retString;
- }
- }
- }
3.调用模拟post表单
- var url = "http://127.0.0.1/testformdata.aspx?aa=1&bb=2&ccc=3";
- var log1=@"D:\temp\log1.txt";
- var log2 = @"D:\temp\log2.txt";
- var formDatas = new List<Grass.Net.FormItemModel>();
- formDatas.Add(new Grass.Net.FormItemModel()
- {
- Key="log1",
- Value="",
- FileName = "log1.txt",
- FileContent=File.OpenRead(log1)
- });
- formDatas.Add(new Grass.Net.FormItemModel()
- {
- Key = "log2",
- Value = "",
- FileName = "log2.txt",
- FileContent = File.OpenRead(log2)
- });
- formDatas.Add(new Grass.Net.FormItemModel()
- {
- Key = "id",
- Value = "id-test-id-test-id-test-id-test-id-test-"
- });
- formDatas.Add(new Grass.Net.FormItemModel()
- {
- Key = "name",
- Value = "name-test-name-test-name-test-name-test-name-test-"
- });
- var result = PostForm(url, formDatas);
转载自 http://blog.csdn.net/xxj_jing/article/details/50221113
c# 模拟表单提交,post form 上传文件、大数据内容
原文:http://www.cnblogs.com/flish/p/5898441.html