URLDownloadToCacheFile

[9Mark9]

Hi,

When I use URLDownloadToCacheFile in my VB Code, I receive the following error:

DLL-Entry Point URLDownloadToCacheFile in URLMON.dll not found

My system is Windows 2000 Professional. urlmon.dll is very likely the most recent version, since it just got updated during a Windows Update (got the same error before the update).
Version Number: 6.0.2800.1400

To make things more confusing: URLDownloadToFile works without a problem, EVEN when I UNREGISTER c:\winnt\system32\urlmon.dll ! How is that possible?

Thanks for your help.

[manavo11]

Maybe your mean to use the URLDownloadToFile API? I couldn't find a URLDownloadToCacheFile API...

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

[9Mark9]

Found the solution to my problem. Have to use an alias in the API declaration. This works:

Private Declare Function URLDownloadToCacheFile Lib "urlmon" Alias "URLDownloadToCacheFileA" ( _
ByVal lpUnkcaller As Long, _
ByVal szURL As String, _
ByVal szFileName As String, _
ByVal dwBufLength As Long, _
ByVal dwReserved As Long, _
ByVal IBindStatusCallback As Long) As Long

[VBAhack]

Hi, I'm like to use this API. Can you post a simple code example showing how to use it? Thanks.

VBAhack

[9Mark9]

Hope this will help:

Private Declare Function URLDownloadToCacheFile Lib "urlmon" Alias "URLDownloadToCacheFileA" ( _
   ByVal lpUnkcaller As Long, _
   ByVal szURL As String, _
   ByVal szFileName As String, _
   ByVal dwBufLength As Long, _
   ByVal dwReserved As Long, _
   ByVal IBindStatusCallback As Long) As Long
    
Private Const E_FAIL As Long = &H80004005
Private Const E_OUTOFMEMORY As Long = &H8007000E
Private Const S_OK As Long = &H0
Private Const MAX_PATH  As Long = 260
 
Private Function DownloadPic(myUrl As String) As String
   Dim retValue As Long
   Dim localFileName As String
   
   On Error GoTo trackError
      
   'prepare  the  variable  that  will  be  filled  with  the name that the file, once
   'downloaded, receives.
   localFileName = Space$(MAX_PATH)
   
   'if  the url was already downloaded into the cache and exists there, it
   'is not downloaded again. Instead, localFileName receives the name of the file that
   'is already in the Cache
   retValue = URLDownloadToCacheFile(0, myUrl, localFileName, Len(localFileName), 0, 0)
   
   If retValue = S_OK Then
      DownloadPic = Left$(localFileName, InStr(localFileName, vbNullChar) - 1)
   Else
      DownloadPic = vbNullString
   End If
   
   Exit Function
   
trackError:
 
DownloadPic = vbNullString
 
End Function

[VBAhack]

Thanks very much. Tried it and it works, but I was under the mistaken impression that the cache was RAM, not disk. Thus, the only difference between URLDownloadToFile and URLDownloadToCacheFile is that with the former, you need to specify the name/path where you want the file saved. Thanks for helping to make the differences clear.

VBAhack