Question

VB6从数据库或服务器上拿到base64编码的字符串(图片数据),如何解码并保存在指定的文件夹里头,求大神帮忙.

Private Sub ShowPicture(msg As String)
On Error GoTo ErrHand
Dim strS() As String
Dim byData As String
Dim pic() As Byte
Dim c1 As New Class1
''向服务器发送接收图片请求 bbb为请求ID
Dim objHTTP As Object
Set objHTTP = CreateObject("MSXML2.ServerXMLHTTP")
objHTTP.setTimeouts 20000, 20000, 20000, 20000
objHTTP.open "GET", WsServer & "servlet/DoDownloadBackground?id=" & msg
objHTTP.send
lmsg "msg" & msg
byData = objHTTP.responseText '接收字符串
'Text5.Text = c1.Base64Decode(Text3.Text)
pic = c1.Base64Decode(byData) 'base64解码
'pic = c2.DecodeBase64StringToFile(byData, 0)
'接收文件'
Open "D:" & "\" & msg & ".jpg" For Binary As #1
Put #1, , pic
Close #1
ErrHand:
'Me.SetFocus
lmsg "ShowMsg:::: Error: " & err.Description
End Sub
这里能保存但是不可以打开图片查看,

Answer 1

Private Declare Function CreateStreamOnHGlobal Lib "ole32.dll" ( _
                          ByVal hGlobal As Long, _
                          ByVal fDeleteOnRelease As Long, _
                          lpIStream As IUnknown) As Long

Private Declare Function OleLoadPicture Lib "oleaut32.dll" ( _
                          ByVal lpStream As IUnknown, _
                          ByVal lSize As Long, _
                          ByVal fRunmode As Long, _
                          riid As Any, _
                          lpIPicture As IPicture) As Long
Function ByteToPict(PictureData() As Byte) As StdPicture 'Byte转图片
    Dim IID_IPicture(3) As Long
    Dim oPicture As IPicture
    Dim nResult As Long
    Dim oStream As IUnknown
    Dim hGlobal As Long
    IID_IPicture(0) = &H7BF80980
    IID_IPicture(1) = &H101ABF32
    IID_IPicture(2) = &HAA00BB8B
    IID_IPicture(3) = &HAB0C3000
    Call CreateStreamOnHGlobal(VarPtr(PictureData(LBound(PictureData))), 0, oStream)
    nResult = OleLoadPicture(oStream, 0, 0, IID_IPicture(0), oPicture)
    If nResult = 0 Then
        Set ByteToPict = oPicture
    End If
End Function

先把byte转为StdPicture再进行SavePicture