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。