This Article Was previously Published Under Q165298
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Summarymore informationReferences
Summary
TO Properly Simulate A Formission Using Wininet, You NEED TO Send A Header That INDICES The Proper Content-Type. For Forms, The Proper Content-Type Header IS:
Content-Type: Application / X-WWW-FORM-URLENCODED
More information
In many cases, the server does not respond appropriately if a Content-Type is not specified. For example, the Active Server Pages component of IIS 3.0 actually checks this header specifically for 'application / x-www-form- urlencoded' before adding form variables to the "Request.Form" object. This MIME / Content-Type indicates that the data of the request is a list of URL- encoded form variables. URL-encoding means that space character (ASCII 32) is encoded as ' ' , Special Character Such '!' Encoded in Hexadecimal Form as '% 21'.
Here Is A Snippet of Code That The MFC Wininet Classes To Simulate A Form Post Request:
CString strheaders =
_T ("Content-Type: Application / X-WWW-FORM-URLENCODED");
// URL-Encoded Form Variables -
// Name = "john doe", userid = "hithere", other = "p & q"
CSTRING STRFORMDATA = _T ("Name = John Doe & Userid = Hithere & Other = P% 26Q");
CinternetSession session;
ChttpConnection * PConnection =
Session.getttpConnection (_T ("ServerNameHere");
Chttpfile * pfile =
PConnection-> OpenRequest (ChttpConnection :: http_verb_post,
_T ("formactionhere"));
Bool result = pfile-> sendrequest (strheaders,
(LPCTSTSTR) StrformData, StrformData.getlength ());
WITHOUT MFC, The Same Code Translates To Straight SDK Calls as Follows: Static Tchar HDRS [] =
_T ("Content-Type: Application / X-WWW-FORM-URLENCODED");
Static tchar frmdata [] =
_T ("name = john doe & userid = Hithere & other = p% 26Q");
Static LPSTR Accept [2] = {"* / *", null};
// for Clarity, Error-Checking Has Been Removed
Hinternet hsession = Internetopen ("MyAgent",
Internet_Open_Type_Preconfig, NULL, NULL, 0);
Hinternet hconnect = InternetConnect (HSession, _T ("ServerNameHere"),
Internet_Default_http_port, null, null, internet_service_http, 0, 1);
Hinternet hRequest = httpopenRequest (hconnect, "post",
_T ("formactionhere"), NULL, NULL, Accept, 0, 1);
HttpsendRequest (HREQUEST, HDRS, STRLEN (HDRS), FRMDATA, STRLEN (FRMDATA);
// Close Any Valid Internet-Handles
References
For More Information About URL-Encoding and the Format of A Form Post Request, See Section 8.2 in RFC 1866.
