Console::WriteLine("contents of {0}:", fileName); while (br->BaseStream->Position < br->BaseStream->Length) Console::WriteLine(br->ReadInt32().ToString());
Function Gethttpdownload(sUrl As String) As boolen
Dim s As String Dim hOpen As Long Dim hOpenUrl As Long Dim bDoLoop As Boolean Dim bRet As Boolean Dim sReadBuffer As String * 2048 Dim lNumberOfBytesRead As Long hOpen = InternetOpen(scUserAgent, INTERNET_OPEN_TYPE_PRECONFIG, vbNullString, vbNullString, 0) hOpenUrl = InternetOpenUrl(hOpen, sUrl, vbNullString, 0, INTERNET_FLAG_RELOAD, 0) bDoLoop = True Do While bDoLoop sReadBuffer = vbNullString bRet = InternetReadFile(hOpenUrl, sReadBuffer, Len(sReadBuffer), lNumberOfBytesRead) s = s & Left$(sReadBuffer, lNumberOfBytesRead) If Not CBool(lNumberOfBytesRead) Then bDoLoop = False Loop FileName = "E:\BitSpirit\Torrent\121212.torrent" F1 = FreeFile Open FileName For Binary As F1 Put F1, , s Close F1 If hOpen <> 0 Then InternetCloseHandle (hOpen) Gethttpdownload = true End Function
上面方法,用来获取服务器上的文本类型的文件一点问题,都没有,但是用来下载二进制文件的时候 就出现问题了,里面的数据怎么也不对,研究了下载下来的文件后发现,问题外话应该是在接收数据的变量是个STRING的定长字符串上。但是在网上查了好久,甚至M$ MSDN上的一个用VB来实现下载的程也是用 string类型来接收数据的而且网上的代码写法,基本上也都是这个样,好来才好现,都是从MSDN上的哪个例程上演变过来的. 我想如果能用一个byte数组来代替定长字符串,哪可能就没有问题了,但是查看了一个VB 对Internetreadfile的申明 Public Declare Function InternetReadFile Lib "wininet.dll" (ByVal hFile As Long, ByVal sBuffer As String, ByVal lNumBytesToRead As Long, lNumberOfBytesRead As Long) As Integer 发现其定义ByVal sBuffer As String 看来只能用String了,在网上查找过程中,发现人家用VC写的程序中这人参数可以是其它的,所以查看了一下Internetreadfile的原型。发现的确可以, 所以我把internetreadfile的定义修改了一下,为了通用,我为新的internetreadfile定义了一个别名。Internetreadfilebyte申明如下: Public Declare Function InternetReadFileByte Lib "wininet.dll" Alias "InternetReadFile" (ByVal hFile As Long, ByRef sBuffer As Byte, ByVal lNumBytesToRead As Long, lNumberOfBytesRead As Long) As Integer 试了一下的确可以,重新修改函数,(在这过程中发现,如果要取到正确数据,还必须取得文件大小。所以增加了HttpQueryInfo的定义)最后完整的函数 Function FileDownload(sUrl As Variant) As Boolean Dim b(99) As Byte Dim EndByte() As Byte Dim s As String Dim hOpen As Long Dim hOpenUrl As Long Dim bDoLoop As Boolean Dim bRet As Boolean Dim bbuffer As Byte Dim sReadBuffer As String Dim FileName As String Dim lNumberOfBytesRead As Long Dim F1 As Integer Dim strsize As String Dim size As Long strsize = String$(1024, " ")
F1 = FreeFile stTotal = vbNullString FileName = "E:\BitSpirit\Torrent\121212.torrent" Open FileName For Binary As F1 hOpen = InternetOpen(scUserAgent, INTERNET_OPEN_TYPE_PRECONFIG, vbNullString, vbNullString, 0) hOpenUrl = InternetOpenUrl(hOpen, sUrl, vbNullString, 0, INTERNET_FLAG_RELOAD, 0) bDoLoop = True HttpQueryInfo hOpenUrl, HTTP_QUERY_CONTENT_LENGTH Or HTTP_QUERY_FLAG_NUMBER, ByVal strsize, Len(strsize), 0 size = CLng(Trim(strsize)) For j = 1 To size \ 100 bDoLoop = InternetReadFileByte(hOpenUrl, b(0), 100, lNumberOfBytesRead)
Put F1, , b If Not CBool(lNumberOfBytesRead) Then Exit For Next If size Mod 100 <> 0 Then tmp = (size Mod 100) - 1 ReDim EndByte(tmp) bDoLoop = InternetReadFileByte(hOpenUrl, EndByte(0), tmp + 1, lNumberOfBytesRead) Put F1, , EndByte End If
If hOpenUrl <> 0 Then InternetCloseHandle (hOpenUrl) If hOpen <> 0 Then InternetCloseHandle (hOpen)
Close #1 FileDownload = True End Function 测试了一下,完全成功:)
'读文件至变量 Private Sub Command1_Click() dim FileName As String Dim i As Integer, s As String, BB() As Byte FileName="c:\1.dat" If Dir(FileName) = "" Then Exit sub i = FreeFile ReDim BB(FileLen(FileName) - 1)'按文件长度读取 Open FileName For Binary As #i Get #i, , BB Close #i s=bb '*****适用于非文本文件***** 's = StrConv(BB, vbUnicode) '*****适用于文本文件***** End Sub