在上一篇中，我们说了模拟登录，
下面我们说说附件上传。
据说，最早的http协议是不支持附件上传的，后来有添加了一个RFC 2045 协议，才支持附件上传，关于附件上传，请参见
http://www.cnblogs.com/greenerycn/archive/2010/05/15/csharp_http_post.html
好了，其实用C#模拟上传附件，主要的难点就在于如何构建此协议的格式以及编码。
作为备忘，我这里只放一段成品代码了。
参数：URL,上传控件的id，附件的本地全路径，传输的Key-value数据
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public string HttpWebUpload(string url, string fileControlID, string fileFullPath, Dictionary<string, string> dic) { string fileContentType = "application/octet-stream";//"application/octet-stream";//"text/plain";//image/jpeg int index = fileFullPath.LastIndexOf(‘\\‘); string filename = fileFullPath.Substring(index+1); var boundary = DateTime.Now.Ticks.ToString("x"); var beginBoundary = "--" + boundary; var reqContentType = "multipart/form-data; boundary=" + boundary; var memStream = new MemoryStream(); var fileStream = new FileStream(fileFullPath, FileMode.Open, FileAccess.Read); int fsLen = (int)fileStream.Length; byte[] btfileValue = new byte[fsLen]; int r = fileStream.Read(btfileValue, 0, btfileValue.Length); StringBuilder fileHeader = new StringBuilder(); fileHeader.AppendLine(beginBoundary); fileHeader.AppendLine(string.Format("Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"", fileControlID, filename)); fileHeader.AppendLine(string.Format("Content-Type: {0}", fileContentType)); fileHeader.AppendLine(); var btfileKey = Encoding.UTF8.GetBytes(fileHeader.ToString()); StringBuilder dicData = new StringBuilder(); dicData.AppendLine(); foreach (var item in dic) { dicData.AppendLine(beginBoundary); dicData.AppendLine(string.Format("Content-Disposition:form-data; name=\"{0}\"", item.Key)); dicData.AppendLine(); dicData.AppendLine(item.Value); } dicData.AppendLine(beginBoundary + "--"); var btDic = Encoding.UTF8.GetBytes(dicData.ToString()); HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url); req.Method = "POST"; req.AllowAutoRedirect = false; req.ContentType = reqContentType; if (!string.IsNullOrEmpty(UserAgent)) { req.UserAgent = this.UserAgent; } if (!string.IsNullOrEmpty(Cookie)) { req.CookieContainer = new CookieContainer(); req.CookieContainer.SetCookies(req.RequestUri, this.Cookie); } req.ContentLength = btfileKey.Length + btfileValue.Length + btDic.Length; Stream postDataStream = req.GetRequestStream(); postDataStream.Write(btfileKey, 0, btfileKey.Length); postDataStream.Write(btfileValue, 0, btfileValue.Length); postDataStream.Write(btDic, 0, btDic.Length); postDataStream.Close(); HttpWebResponse resp = (HttpWebResponse)req.GetResponse(); string html = new StreamReader(resp.GetResponseStream()).ReadToEnd(); return html; } |
注意，这里如果需要cookie,则添加对应的cookie。
调用方法
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string controlid = "fupCert";string filefullPath = "f:\\3.pdf";string url = "http://10.35.3.240/NT_HandbookExtend/FrmCertificate.aspx?type=N&zdtype=J&DELEGATENO=SBWJ16100001&ID=SB20161018000001%2c3206960757&Action=Modify&manualRecordID=SL20161018000001&tm=0.17032586549994377";var hiddenVal = web.GetDoNetHiddenValuesByUrl(url);//获取__VIEWSTATE，与__EVENTVALIDATION隐藏域值Dictionary<string, string> dic = new Dictionary<string, string>();dic.Add("__EVENTARGUMENT", "");dic.Add("__EVENTTARGET", "btnUpload");dic.Add("__EVENTVALIDATION", hiddenVal.Eventvalidation);dic.Add("__PREVIOUSPAGE", "EncayjCF95BJXxMazWGgd9UdPYeLp64GjuJlZ-rvnQ5n34-y7KQYllE35nAdVFvk0");dic.Add("__VIEWSTATE", hiddenVal.Vievstate);dic.Add("__VIEWSTATEENCRYPTED", "");dic.Add("grdNavigatorPRE_EMS3_CUS_IMG$ctl06", "");dic.Add("grdNavigatorPRE_EMS3_CUS_IMG$ctl07", "15");dic.Add("grdNavigatorPRE_EMS3_CUS_IMG$labelRowCount", "8");dic.Add("hfERP", "http://www.nteport.gov.cn/cerp/platform/erp/documentManagement/documentDocking.jsp");dic.Add("hidFileType", "333");dic.Add("hidID", "");//web.UserAgent = "Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0)";string html = web.HttpWebUpload(url, controlid, filefullPath, dic); |
其他注意事项：
1.如果不限制文件类型，请使用 ContentType = "application/octet-stream";这个我也没怎么懂，尴尬。。。
2. 编码很重要，由于传参时，都是以流的形式传参，所以文件编码使用默认的编码方式，和其他构建的RFC 2045 协议格式，使用UTF-8编码。