CopyURLToFile – Download a file from the Internet via FTP or HTTP

CopyURLToFile – Download a file from the Internet via FTP or HTTP

Const INTERNET_OPEN_TYPE_PRECONFIG = 0Const INTERNET_FLAG_EXISTING_CONNECT = &H20000000Private Declare Function InternetOpen Lib "wininet.dll" Alias "InternetOpenA" _    (ByVal lpszAgent As String, ByVal dwAccessType As Long, _    ByVal lpszProxyName As String, ByVal lpszProxyBypass As String, _    ByVal dwFlags As Long) As LongPrivate Declare Function InternetOpenUrl Lib "wininet.dll" Alias _    "InternetOpenUrlA" (ByVal hInternetSession As Long, ByVal lpszUrl As String, _    ByVal lpszHeaders As String, ByVal dwHeadersLength As Long, _    ByVal dwFlags As Long, ByVal dwContext As Long) As LongPrivate Declare Function InternetCloseHandle Lib "wininet.dll" (ByVal hInet As _    Long) As IntegerPrivate Declare Function InternetReadFile Lib "wininet.dll" (ByVal hFile As _    Long, ByVal lpBuffer As String, ByVal dwNumberOfBytesToRead As Long, _    lNumberOfBytesRead As Long) As Integer' Download a file from Internet and save it to a local file'' it works with HTTP and FTP, but you must explicitly include' the protocol name in the URL, as in'    CopyURLToFile "", "C:vb2themax.htm"Sub CopyURLToFile(ByVal URL As String, ByVal FileName As String)    Dim hInternetSession As Long    Dim hUrl As Long    Dim FileNum As Integer    Dim ok As Boolean    Dim NumberOfBytesRead As Long    Dim Buffer As String    Dim fileIsOpen As Boolean    On Error GoTo ErrorHandler    ' check obvious syntax errors    If Len(URL) = 0 Or Len(FileName) = 0 Then Err.Raise 5    ' open an Internet session, and retrieve its handle    hInternetSession = InternetOpen(App.EXEName, INTERNET_OPEN_TYPE_PRECONFIG, _        vbNullString, vbNullString, 0)    If hInternetSession = 0 Then Err.Raise vbObjectError + 1000, , _        "An error occurred calling InternetOpen function"    ' open the file and retrieve its handle    hUrl = InternetOpenUrl(hInternetSession, URL, vbNullString, 0, _        INTERNET_FLAG_EXISTING_CONNECT, 0)    If hUrl = 0 Then Err.Raise vbObjectError + 1000, , _        "An error occurred calling InternetOpenUrl function"    ' ensure that there is no local file    On Error Resume Next    Kill FileName    On Error GoTo ErrorHandler        ' open the local file    FileNum = FreeFile    Open FileName For Binary As FileNum    fileIsOpen = True    ' prepare the receiving buffer    Buffer = Space(4096)        Do        ' read a chunk of the file - returns True if no error        ok = InternetReadFile(hUrl, Buffer, Len(Buffer), NumberOfBytesRead)        ' exit if error or no more data        If NumberOfBytesRead = 0 Or Not ok Then Exit Do                ' save the data to the local file        Put #FileNum, , Left$(Buffer, NumberOfBytesRead)    Loop        ' flow into the error handlerErrorHandler:    ' close the local file, if necessary    If fileIsOpen Then Close #FileNum    ' close internet handles, if necessary    If hUrl Then InternetCloseHandle hUrl    If hInternetSession Then InternetCloseHandle hInternetSession        ' report the error to the client, if there is one    If Err Then Err.Raise Err.Number, , Err.DescriptionEnd Sub

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