40分！GDI+转换图形文件数据到StdPicture，怎么释放Stream

2013-04-26

40分！GDI+转换图形文件数据到StdPicture，如何释放Stream？本帖最后由 liucqa 于 2013-04-15 21:14:28 编辑P

40分！GDI+转换图形文件数据到StdPicture，如何释放Stream？
本帖最后由 liucqa 于 2013-04-15 21:14:28 编辑

Public Function body2Image(ByRef imgbody() As Byte) As StdPicture
    Dim iWidth As Long     '以像素为单位的图形宽度
    Dim iHeight As Long    '以像素为单位的图形高度
    Dim lStream As Long
    Dim hDC As Long, hDCmem As Long, lrtn As Long

    Dim lBitmap As Long
    Dim hBitmap As Long
    Dim tPictDesc As PicBmp
    Dim IID_IPicture As GUID
    Dim oPicture As StdPicture

    Call GDI_Initialize
    'hDC = GetDC(0)

    Call CreateStreamOnHGlobal(imgbody(0), False, lStream)
    '从Stream加载Bitmap
    If GdipLoadImageFromStream(lStream, lBitmap) = OK Then
        '根据Bitmap创建hBitbmp
        If GdipCreateHBITMAPFromBitmap(lBitmap, hBitmap, 0) = OK Then
            With tPictDesc
                .Size = Len(tPictDesc)
                .Type = vbPicTypeBitmap
                .hBmp = hBitmap
                .hPal = 0
            End With

            ' 初始化IPicture
            With IID_IPicture
                .Data1 = &H7BF80981
                .Data2 = &HBF32
                .Data3 = &H101A
                .Data4(0) = &H8B
                .Data4(1) = &HBB
                .Data4(3) = &HAA
                .Data4(5) = &H30
                .Data4(6) = &HC
                .Data4(7) = &HAB
            End With

            Call OleCreatePictureIndirect(tPictDesc, IID_IPicture, True, oPicture)
            Set body2Image = oPicture

        End If
    End If
    GdipDisposeImage lBitmap    '释放lBitmap
    'Call ReleaseDC(0, hDC)
    Call GDI_Terminate
End Function

请问上面的代码中，lStream是否需要释放？如何释放呢？
这段代码是否还有内存泄漏问题？

[解决办法]
不用释放,销毁GDI+就OK了.
[解决办法]
接下来讲一个不使用类型库释放对象的小技巧：

'释放IStream对象
Private Function ReleaseStream(ByVal lpStream As Long) As Boolean
     Dim lpThis As Long
     Dim lpVTable As Long

     Dim oTmp As Collection

     If lpStream = 0 Then Exit Function

     Set oTmp = New Collection

     lpThis = ObjPtr(oTmp)

     CopyMemory lpVTable, ByVal lpThis, 4

     CopyMemory ByVal lpThis, ByVal lpStream, 4
     Set oTmp = Nothing
     CopyMemory ByVal lpThis, lpVTable, 4

     Set oTmp = Nothing
     ReleaseStream = True
End Function

以上复制自CSDN

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40分！GDI+转换图形文件数据到StdPicture，怎么释放Stream