参数不是可选的

Question

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

Sub AAA()                                                   
  Dim SourceName As String
  Dim Destination As String
  Dim R As Long

  SourceName = "http://www.cpearson.com/zips/modDownloadFile.zip"
  Destination = "D:\Test\modDownloadFile.zip"
  R = URLDownloadToFile(0&, SourceName, Destination, 0&, 0&)
  If R = 0 Then
      Debug.Print "success"
  Else
    Debug.Print "error: " & CStr(Err.LastDllError)
  End If
End Sub                                  

Answer 1

请尝试URLDownloadToFile(0, SourceName, Destination, 0, 0)而不是URLDownloadToFile(0&, SourceName, Destination, 0&, 0&)。