C # Use webrequest (httprequest) to send files

Use httprequest in the C # system.net library to send a specified field of a file to the specified web server, and simulate the get part and cookies. </P> <p> using system; <br/> using system. collections. generic; <br/> using system. text; <br/> using system. collections. specialized; <br/> using system. net; <br/> using system. net. sockets; <br/> using system. io; <br/> namespace completeclient <br/> {<br/> // <summary> <br/> // File Sending work class <br/> // </ summary> <br/> class postfile <br/> {<Br/> /// <summary> <br/> // send the specified field of the specified file to the specified URI through post <br/> /// </ summary> <br/> /// <Param name = "uploadfile"> Upload File Path </param> <br/> /// <Param name = "url"> upload </param> <br/> // <Param name = "offset"> current offset </param> <br/> // <Param name = "size"> size of the block to be sent </param> <br/> // <Param name = "fileformname"> file name obtained by the server "get" </Param> <br/> // <Param name = "contenttype"> file type (Reserved) </param> <br/> /// <Param n Ame = "querystring"> Get array (for the server to get some information with get) </param> <br/> // <Param name = "cookies"> Local cookies (Reserved) </param> <br/> /// <returns> the response content of the URI is returned as a string </returns> <br/> Public String uploadfileex (string uploadfile, string URL, long offset, long size, <br/> string fileformname, string contenttype, <br/> namevaluecollection querystring, cookiecontainer cookies) <br/>{< br/> If (fileformname = NULL) | <Br/> (fileformname. length = 0) <br/>{< br/> fileformname = "file "; <br/>}</P> <p> If (contenttype = NULL) ||< br/> (contenttype. length = 0) <br/>{< br/> contenttype = "application/octet-stream"; <br/>}</P> <p> string postdata; <br/> postdata = "? "; <Br/> If (querystring! = NULL) <br/>{< br/> foreach (string key in querystring. keys) <br/>{< br/> postdata + = Key + "=" + querystring. get (key) + "&"; <br/>}< br/> URI uri = new uri (URL + postdata ); </P> <p> string boundary = "----------" + datetime. now. ticks. tostring ("X"); <br/> httpwebrequest webrequest = (httpwebrequest) webrequest. create (URI); <br/> webrequest. cookiecontainer = cookies; <br/> webrequest. contenttype = "multipart/form-data; boundary =" + boundary; <br/> webrequest. method = "Post"; </P> <p> // construct the HTTP header of a POST request <br/> stringbuilder sb = new stringbuilder (); <br/> Sb. append ("--"); <br/> Sb. append (Boundary); <br/> Sb. append ("/R/N"); <br/> Sb. append ("content-Disposition: Form-data; name =/" "); <br/> Sb. append (fileformname); <br/> Sb. append ("/"; filename =/""); <br/> Sb. append (path. getfilename (uploadfile); <br/> Sb. append ("/" "); <br/> Sb. append ("/R/N"); <br/> Sb. append ("Content-Type:"); <br/> Sb. append (contenttype); <br/> Sb. append ("/R/N"); <br/> Sb. append ("/R/N"); </P> <p> string postheader = sb. tostring (); <br/> byte [] postheaderbytes = encoding. utf8.getbytes (postheader ); </P> <p> // build the trailing boundary string as a byte array <br/> // ensuring the Boundary appears on a line by itself <br/> byte [] boundarybytes = <br/> encoding. ASCII. getbytes ("/R/n --" + boundary + "/R/N"); </P> <p> filestream = new filestream (uploadfile, <br/> filemode. open, fileaccess. read); <br/> long length = postheaderbytes. length + (long) size + <br/> boundarybytes. length; <br/> webrequest. contentlength = length; </P> <p> stream requeststream = webrequest. getrequeststream (); <br/> // write the post header <br/> requeststream. write (postheaderbytes, 0, postheaderbytes. length); </P> <p> // Write File content <br/> byte [] buffer = new byte [size]; <br/> filestream. seek (offset, seekorigin. current); <br/> filestream. read (buffer, 0, buffer. length); </P> <p> requeststream. write (buffer, 0, buffer. length); </P> <p> // write the end of the post request <br/> requeststream. write (boundarybytes, 0, boundarybytes. length); <br/> // read the server feedback message <br/> webresponse Responce = webrequest. getresponse (); <br/> stream S = Responce. getresponsestream (); <br/> streamreader sr = new streamreader (s); </P> <p> return Sr. readtoend (); <br/>}< br/>