下载文件 – VB6

如果您只想使用代码(没有Internet传输控制),VBNet.mvps.org有一篇非常好的使用URLDownloadToFile API调用的how-to文章.

来自文章：

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 Const ERROR_succesS As Long = 0
Private Const BINDF_GETNEWestVERSION As Long = &H10
Private Const INTERNET_FLAG_RELOAD As Long = &H80000000

Public Function DownloadFile(ssourceUrl As String,_
                             sLocalFile As String) As Boolean

  //'Download the file. BINDF_GETNEWestVERSION forces 
  //'the API to download from the specified source. 
  //'Passing 0& as dwReserved causes the locally-cached 
  //'copy to be downloaded,if available. If the API 
  //'returns ERROR_succesS (0),DownloadFile returns True.
   DownloadFile = URLDownloadToFile(0&,_
                                    ssourceUrl,_
                                    sLocalFile,_
                                    BINDF_GETNEWestVERSION,_
                                    0&) = ERROR_succesS

End Function

仅供参考 – 在Windows 7上进行测试时,它只会返回缓存版本,因此我必须先使用文章中提到的额外功能来清除它(并且可以正常工作).

Private Declare Function deleteUrlCacheEntry Lib "Wininet.dll" _
   Alias "deleteUrlCacheEntryA" _
  (ByVal lpszUrlName As String) As Long

然后,首先使用目标URL调用上述函数,以清除缓存.