Chip 2005 June/CHIP 2005-06.iso/program/yazilim/myscreencapture.exe/{app}/Demo VB6/cDIBSectionmod.cls

Visual Basic class definition | 2004-10-13 | 6.0 KB | 177 lines

VERSION 1.0 CLASS
BEGIN
  MultiUse = -1  'True
  Persistable = 0  'NotPersistable
  DataBindingBehavior = 0  'vbNone
  DataSourceBehavior  = 0  'vbNone
  MTSTransactionMode  = 0  'NotAnMTSObject
END
Attribute VB_Name = "cDIBSection"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = True
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Option Explicit
'
'This is an example showing how to save a picture into JPEG format
'using the INTEL FREE Library.
'There is NO SUPPORT on this part of code.
'
'If you don't need to save in JPEG format the capture, you don't need to
'include this part of code in your application.
'

' ==================================================================================
' Requires:    mIJLmod.cls
'              ijl15.dll (Intel)
' ==================================================================================

Private Type RGBQUAD
    rgbBlue As Byte
    rgbGreen As Byte
    rgbRed As Byte
    rgbReserved As Byte
End Type
Private Type BITMAPINFOHEADER '40 bytes
    biSize As Long
    biWidth As Long
    biHeight As Long
    biPlanes As Integer
    biBitCount As Integer
    biCompression As Long
    biSizeImage As Long
    biXPelsPerMeter As Long
    biYPelsPerMeter As Long
    biClrUsed As Long
    biClrImportant As Long
End Type
Private Type BITMAPINFO
    bmiHeader As BITMAPINFOHEADER
    bmiColors As RGBQUAD
End Type
Private Declare Function CreateCompatibleDC Lib "gdi32" (ByVal hDC As Long) As Long
Private Declare Function GetDC Lib "user32" (ByVal hwnd As Long) As Long

Private Declare Function GetDesktopWindow Lib "user32" () As Long
Private Declare Function CreateDIBSection Lib "gdi32" (ByVal hDC As Long, pBitmapInfo As BITMAPINFO, ByVal un As _
    Long, lplpVoid As Long, ByVal handle As Long, ByVal dw As Long) As Long
Private Declare Function BitBlt Lib "gdi32" (ByVal hDestDC As Long, ByVal X As Long, ByVal Y As Long, ByVal nWidth _
    As Long, ByVal nHeight As Long, ByVal hSrcDC As Long, ByVal xSrc As Long, ByVal ySrc As Long, ByVal dwRop As _
    Long) As Long
Private Declare Function SelectObject Lib "gdi32" (ByVal hDC As Long, ByVal hObject As Long) As Long
Private Declare Function DeleteObject Lib "gdi32" (ByVal hObject As Long) As Long
Private Declare Function DeleteDC Lib "gdi32" (ByVal hDC As Long) As Long
Private Const BI_RGB = 0&
Private Const BI_RLE4 = 2&
Private Const BI_RLE8 = 1&
Private Const DIB_RGB_COLORS = 0 '  color table in RGBs
Private Type BITMAP
    bmType As Long
    bmWidth As Long
    bmHeight As Long
    bmWidthBytes As Long
    bmPlanes As Integer
    bmBitsPixel As Integer
    bmBits As Long
End Type
Private Declare Function GetObjectAPI Lib "gdi32" Alias "GetObjectA" (ByVal hObject As Long, ByVal nCount As Long, _
    lpObject As Any) As Long

' Handle to the current DIBSection:
Private m_hDIb As Long
' Handle to the old bitmap in the DC, for clear up:
Private m_hBmpOld As Long
' Handle to the Device context holding the DIBSection:
Private m_hDC As Long
' Address of memory pointing to the DIBSection's bits:
Private m_lPtr As Long
' Type containing the Bitmap information:
Private m_tBI As BITMAPINFO

Public Property Get BytesPerScanLine() As Long
    ' Scans must align on dword boundaries:
    BytesPerScanLine = (m_tBI.bmiHeader.biWidth * 3 + 3) And &HFFFFFFFC
End Property

Public Property Get Width() As Long
    Width = m_tBI.bmiHeader.biWidth
End Property

Public Property Get Height() As Long
    Height = m_tBI.bmiHeader.biHeight
End Property

Public Sub LoadPictureBlt(ByVal lhDC As Long, Optional ByVal lSrcLeft As Long = 0, Optional ByVal lSrcTop _
        As Long = 0, Optional ByVal lSrcWidth As Long = -1, Optional ByVal lSrcHeight As Long = -1, Optional ByVal _
        eRop As RasterOpConstants = vbSrcCopy)
    If lSrcWidth < 0 Then lSrcWidth = m_tBI.bmiHeader.biWidth
    If lSrcHeight < 0 Then lSrcHeight = m_tBI.bmiHeader.biHeight
    BitBlt m_hDC, 0, 0, lSrcWidth, lSrcHeight, lhDC, lSrcLeft, lSrcTop, eRop
End Sub

Public Property Get DIBSectionBitsPtr() As Long
    DIBSectionBitsPtr = m_lPtr
End Property

Public Sub ClearUp()
    If (m_hDC <> 0) Then
        If (m_hDIb <> 0) Then
            SelectObject m_hDC, m_hBmpOld
            DeleteObject m_hDIb
        End If
        DeleteObject m_hDC
    End If
    m_hDC = 0: m_hDIb = 0: m_hBmpOld = 0: m_lPtr = 0
End Sub

Public Function CreateFromPicture(ByRef picThis As StdPicture)
  Dim lhDC As Long
  Dim lhDCDesktop As Long
  Dim lhBmpOld As Long
  Dim tBMP As BITMAP

    GetObjectAPI picThis.handle, Len(tBMP), tBMP
    If (Create(tBMP.bmWidth, tBMP.bmHeight)) Then
        lhDCDesktop = GetDC(GetDesktopWindow())
        If (lhDCDesktop <> 0) Then
            lhDC = CreateCompatibleDC(lhDCDesktop)
            DeleteDC lhDCDesktop
            If (lhDC <> 0) Then
                lhBmpOld = SelectObject(lhDC, picThis.handle)
                LoadPictureBlt lhDC
                SelectObject lhDC, lhBmpOld
                DeleteObject lhDC
            End If
        End If
    End If
End Function

Public Function CreateDIB(ByVal lhDC As Long, ByVal lWidth As Long, ByVal lHeight As Long, ByRef hDib As Long _
        ) As Boolean
    With m_tBI.bmiHeader
        .biSize = Len(m_tBI.bmiHeader)
        .biWidth = lWidth
        .biHeight = lHeight
        .biPlanes = 1
        .biBitCount = 24
        .biCompression = BI_RGB
        .biSizeImage = BytesPerScanLine * .biHeight
    End With
    hDib = CreateDIBSection(lhDC, m_tBI, DIB_RGB_COLORS, m_lPtr, 0, 0)
    CreateDIB = (hDib <> 0)
End Function

Public Function Create(ByVal lWidth As Long, ByVal lHeight As Long) As Boolean
    ClearUp
    m_hDC = CreateCompatibleDC(0)
    If (m_hDC <> 0) Then
        If (CreateDIB(m_hDC, lWidth, lHeight, m_hDIb)) Then
            m_hBmpOld = SelectObject(m_hDC, m_hDIb)
            Create = True
        Else
            DeleteObject m_hDC
            m_hDC = 0
        End If
    End If
End Function