Urlmon and Wininet

[esposito]

Hello, as I am developing a VB6 application thta contains the following API declarations:

Private Declare Function URLDownloadToFile Lib "urlmon" Alias "URLDownloadToFileA" (ByVal pCaller As Long, ByVal szURL As String, ByVal szFileName As String, ByVal dwReserved As Long, ByVal lpfnCB As Long) As Long
Private Declare Function InternetOpen Lib "wininet.dll" Alias "InternetOpenA" (ByVal sAgent As String, ByVal lAccessType As Long, ByVal sProxyName As String, ByVal sProxyBypass As String, ByVal lFlags As Long) As Long

I was wondering whether I must make sure that urlmon and wininet are on the user's computer or I can take it for granted. In other words, are the two libraries above an integral part of Windows? If yes, since when have they been shipped with the OS?

TIA

[DigiRev]

Only way to be sure is to try it, I don't believe you do since those libraries should come already installed with Windows. However, when creating an installation package using those API functions using VB's Package & Deployment Wizard, it adds those files to the support folder.

URLDownloadToFile:
Operating Systems Supported
Requires Windows NT 4.0 or later; Requires Windows 95 or later

InternetOpen:
Operating Systems Supported
Requires Windows NT 4.0 or later; Win9x/ME: Not supported

Taken from:
http://allapi.mentalis.org/apilist

[esposito]

Only way to be sure is to try it, I don't believe you do since those libraries should come already installed with Windows. However, when creating an installation package using those API functions using VB's Package & Deployment Wizard, it adds those files to the support folder.

URLDownloadToFile:
Operating Systems Supported
Requires Windows NT 4.0 or later; Requires Windows 95 or later

InternetOpen:
Operating Systems Supported
Requires Windows NT 4.0 or later; Win9x/ME: Not supported

Taken from:
http://allapi.mentalis.org/apilist

Thanks. I don't understand what they mean by "not supported". In particular, it is unclear to me whether it means that Win9X is not equipped with that library or you cannot install that library on Win9X. Any idea?

[Hack]

You can install the library on anything you want. However, if the OS on which it is installed does not support the functionality included in the source code of these DLLs, then using them is not possible.

That is what they mean.

9X does not support the functionality.

[esposito]

Is there any way I can make the code below compatible with Win 98 and Me? In other words, is it possible to make a different API call (no OCX's) to get the same result under Win 98 and Me?

Option Explicit

Private Declare Function InternetOpen Lib "wininet.dll" Alias "InternetOpenA" (ByVal sAgent As String, ByVal lAccessType As Long, ByVal sProxyName As String, ByVal sProxyBypass As String, ByVal lFlags As Long) As Long
Private Declare Function InternetOpenUrl Lib "wininet.dll" Alias "InternetOpenUrlA" (ByVal hInternetSession As Long, ByVal sURL As String, ByVal sHeaders As String, ByVal lHeadersLength As Long, ByVal lFlags As Long, ByVal lContext As Long) As Long
Private Declare Function InternetReadFile Lib "wininet.dll" (ByVal hFile As Long, ByVal sBuffer As String, ByVal lNumBytesToRead As Long, lNumberOfBytesRead As Long) As Integer
Private Declare Function InternetCloseHandle Lib "wininet.dll" (ByVal hInet As Long) As Integer
Private Declare Function GetInputState Lib "user32" () As Long

Private Const IF_NO_CACHE_WRITE = &H4000000
       
Private Const BUFFER_LEN = 256

Private Function URLSource(ByRef URL As String) As String
    Dim strBuffer As String * BUFFER_LEN, lonRet As Long
    Dim strData As String, lonHandle As Long, lonSession As Long
    Dim lonResult As Long
    
    lonSession = InternetOpen("vb wininet", 1, vbNullString, vbNullString, 0)
    If lonSession Then lonHandle = InternetOpenUrl(lonSession, URL, vbNullString, 0, IF_NO_CACHE_WRITE, 0)
    If lonHandle Then
        lonResult = InternetReadFile(lonHandle, strBuffer, BUFFER_LEN, lonRet)
        strData = strBuffer
        Do While lonRet <> 0
            lonResult = InternetReadFile(lonHandle, strBuffer, BUFFER_LEN, lonRet)
            strData = strData & Mid$(strBuffer, 1, lonRet)
            If GetInputState Then DoEvents
        Loop
    End If
    
    lonResult = InternetCloseHandle(lonHandle)
    URLSource = strData
End Function

Thanks in advance.