Page Comparison

private void button1_Click(object sender, EventArgs e)
{
	int iResultId;
	String strResultText;
	String strResultData;
	String strRequestData = "<?xml version=\"1.0\"?>"
	+ "<image type=\"photo\" format=\"jpg\" ><result data=\"\"/></image>";

	CardSDK.IDProductionService ws = new CardSDK.IDProductionService();
	iResultId = ws.ImageCapture(strRequestData,
		out strResultText, out strResultData);
	if (iResultId == 0)
	{
		// ... strResultData contains the request's response XML which contains
		// the returned image. You may process it using any XML parser
		// (e.g. .NET's XmlDocument)
	}
}

try {
	var req = new XMLHttpRequest();
	var strRequestData = "<?xml version=\"1.0\"?>"
		+ "<image type=\"photo\" format=\"jpg\" ><result data=\"\"/></image>";
	req.open("POST", "ImageCapture", false);
	req.setRequestHeader("Content-Type","text/xml");
	req.send(strRequestData);
	if (req.status == 200) {
		// req.responseText contains the returned XML as string
		// req.responseXML contains the returned XML accessable
		// as XML DOM object
	}
} catch (ex) {
	alert(ex);
}

try {
	var req = new XMLHttpRequest();
	req.onreadystatechange=function() {
		try {
			if (req.readyState==4) {
				if (req.status == 200) {
					// req.responseText contains the returned XML as string
					// req.responseXML contains the returned XML accessable
					// as XML DOM object
				}
			}
		} catch (ex) {
			alert(ex);
		}
	}
	var strRequestData = "<?xml version=\"1.0\"?>"
	+ "<image type=\"photo\" format=\"jpg\" ><result data=\"\"/></image>";
	req.open("POST", "ImageCapture", true);
	req.setRequestHeader("Content-Type","text/xml");
	req.send(strRequestData);
} catch (ex) {
	alert(ex);
}

var date = new Date();
var reloadTrigger = "?"+date.getTime()
req.open("GET", "ImageCapture" + reloadTrigger, false);

XMLHttpRequest (XHR) as used here, is the API to send HTTP requests from within a browser. It is available in the described way in all up-to-date browsers (Mozilla, Opera, Chrome and Internet Explorer). However, the way the IE supports XHR does strongly depend on its version:

• IE 5, 5.5 and 6 support XHR, but require a different object instantiation.
• IE 7 allows the usage as described in this article.
• IE 8 and IE 9 support XHR basically but prevent cross-site requests. This is important in our use case: The HTML page is usually provided by an application server with a domain that is different from the production service's domain. Only in the special case of the IDProductionService, application server and production service domain are identical. Instead, Microsoft introduced the XDomainRequest (XDR) object to make cross-domain requests. XDR is a stripped-down XHD.
• IE 10 allows cross-domain requests using XMLHttpRequest. It can be used in the same way as used with Mozilla, Opera and Chrome.

Using XMLHttpRequest and XDomainRequest directly as shown here is the basic way to communicate with a web service using Java script. However, it may be a more convenient way to use a library like jQuery package (http://jquery.com) or one of its alternatives. For more information, refer to the libraries public documentation. The usage of such libraries may help to solve issues using different browsers and their versions.

TCHAR headers[] = _T("Content-Type: application/x-www-form-urlencoded");
LPSTR accept[2]={"*/*", NULL};
TCHAR requestData[] =
_T("<?xml version=\"1.0\"?><image type=\"photo\" \
format=\"jpg\" ><result data=\"\"/></image>");
HINTERNET hSession = InternetOpen("MyAgent",
	INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
HINTERNET hConnect = InternetConnect(hSession, _T("localhost"),
	54880, NULL, NULL, INTERNET_SERVICE_HTTP, 0, 1);
HINTERNET hRequest = HttpOpenRequest(hConnect, "POST",
	_T("ImageCapture"), NULL, NULL, (LPCTSTR*)accept, 0, 1);
if (HttpSendRequest(hRequest, headers, strlen(headers),
		requestData, strlen(requestData))) {
	TCHAR szHttpInfo[10] = _T("");
	DWORD lenHttpInfo = sizeof(szHttpInfo);
	if (HttpQueryInfo( hRequest, HTTP_QUERY_STATUS_CODE ,
			szHttpInfo, &lenHttpInfo, 0L)) {
		if (_ttoi( szHttpInfo) == 200) { // 200 = OK
			lenHttpInfo = sizeof(szHttpInfo);
			if (HttpQueryInfo( hRequest, HTTP_QUERY_CONTENT_LENGTH,
					szHttpInfo, &lenHttpInfo, 0L)) {
				char* resultData = (char*)LocalAlloc( LPTR, _ttoi( szHttpInfo));
				if (InternetReadFile( hRequest, resultData, _
						ttoi( szHttpInfo), &lenHttpInfo)) {
					// Just for test purposes, we store the received XML into the 
					// file resultData.xml (note the current working directory!)
					DeleteFile( _T("resultData.xml"));
					HANDLE hf = CreateFile( _T("resultData.xml"),
									GENERIC_ALL, 0, 0L, 1, 0x80L, 0);
					if (hf != INVALID_HANDLE_VALUE) {
						WriteFile( hf, resultData, lenHttpInfo, &lenHttpInfo, 0L);
						CloseHandle( hf);
					}
					LocalFree( resultData);
				}
			}
		}
	}
}
InternetCloseHandle( hRequest);
InternetCloseHandle( hConnect);
InternetCloseHandle( hSession);