How can I access an URL through the code

[ssunderk]

In my program, I should be able to access URL using the code in VC++/VB.
I would appreciate if anybody can provide a sample code.

 

[William DePalo [MVP VC++]]

In my program, I should be able to access URL using the code in VC++/VB.
I would appreciate if anybody can provide a sample code.

This is a bare-bones pseudo code sketch using functions in the WinInet API:

InternetConnect(); // Open an HTTP session

HttpOpenRequest(); // Compose an HTTP "GET" transaction

HttpSendRequest(); // Send the "GET" to the web server

HttpQueryInfo(); // Determine the length of the response

InternetReadFile(); // Read the response

InternetCloseHandle(); // Close the HTTP request

InternetCloaseHandle(); // Close the HTTP session

The WinHTTP API is a newer alternative but supported on fewer platforms,
IIRC.

Regards,
Will

 

[Carl Daniel [VC++ MVP]]

In my program, I should be able to access URL using the code in
VC++/VB. I would appreciate if anybody can provide a sample code.

Here's a minimal C++ program to fetch the document from an URL and save it
to a local file.

<code>

#include <windows.h>
#include <tchar.h>
#include <urlmon.h>
#include <stdio.h>

int _tmain(int argc, TCHAR* argv[])
{

if (3 != argc)
{
_tprintf(_T("usage: %0 URL out-file-name"),argv[0]);
return 1;
}

::CoInitialize(0);
TCHAR szFullName[MAX_PATH];
::GetFullPathName(argv[2],MAX_PATH,szFullName,0);
HRESULT hr = ::URLDownloadToFile(
0,
argv[1],
szFullName,
0,
0
);
::CoUninitialize();

if (FAILED(hr))
{
_tprintf(_T("Failed, hr=0x%08x\n"),hr);
return 2;
}


return 0;
}

<code>

You can also very easily fetch from URLs by using the URL Moniker. IIRC,
you can simply call CoGetObject, passing an URL as the "Display Name" and
requesting IStream as the interface. From that IStream you can read the
document into memory, copy it to disk, or whatever.

-cd