bitblt是api函数，看看它的魅力吧

找来的一个例子：'used with fnWeight
Const FW_DONTCARE = 0
Const FW_THIN = 100
Const FW_EXTRALIGHT = 200
Const FW_LIGHT = 300
Const FW_NORMAL = 400
Const FW_MEDIUM = 500
Const FW_SEMIBOLD = 600
Const FW_BOLD = 700
Const FW_EXTRABOLD = 800
Const FW_HEAVY = 900
Const FW_BLACK = FW_HEAVY
Const FW_DEMIBOLD = FW_SEMIBOLD
Const FW_REGULAR = FW_NORMAL
Const FW_ULTRABOLD = FW_EXTRABOLD
Const FW_ULTRALIGHT = FW_EXTRALIGHT
'used with fdwCharSet
Const ANSI_CHARSET = 0
Const DEFAULT_CHARSET = 1
Const SYMBOL_CHARSET = 2
Const SHIFTJIS_CHARSET = 128
Const HANGEUL_CHARSET = 129
Const CHINESEBIG5_CHARSET = 136
Const OEM_CHARSET = 255
'used with fdwOutputPrecision
Const OUT_CHARACTER_PRECIS = 2
Const OUT_DEFAULT_PRECIS = 0
Const OUT_DEVICE_PRECIS = 5
'used with fdwClipPrecision
Const CLIP_DEFAULT_PRECIS = 0
Const CLIP_CHARACTER_PRECIS = 1
Const CLIP_STROKE_PRECIS = 2
'used with fdwQuality
Const DEFAULT_QUALITY = 0
Const DRAFT_QUALITY = 1
Const PROOF_QUALITY = 2
'used with fdwPitchAndFamily
Const DEFAULT_PITCH = 0
Const FIXED_PITCH = 1
Const VARIABLE_PITCH = 2
'used with SetBkMode
Const OPAQUE = 2
Const TRANSPARENT = 1Const LOGPIXELSY = 90
Const COLOR_WINDOW = 5
Const Message = "Hello !"Private Type RECT
    Left As Long
    Top As Long
    Right As Long
    Bottom As Long
End TypePrivate Declare Function GetDeviceCaps Lib "gdi32" (ByVal hdc As Long, ByVal nIndex 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 CreateCompatibleBitmap Lib "gdi32" (ByVal hdc As Long, ByVal nWidth As Long, ByVal nHeight As Long) As Long
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 DeleteDC Lib "gdi32" (ByVal hdc As Long) As Long
Private Declare Function DeleteObject Lib "gdi32" (ByVal hObject As Long) As Long
Private Declare Function CreateEllipticRgn Lib "gdi32" (ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long) As Long
Private Declare Function SetWindowRgn Lib "user32" (ByVal hWnd As Long, ByVal hRgn As Long, ByVal bRedraw As Boolean) As Long
Private Declare Function CreateFont Lib "gdi32" Alias "CreateFontA" (ByVal nHeight As Long, ByVal nWidth As Long, ByVal nEscapement As Long, ByVal nOrientation As Long, ByVal fnWeight As Long, ByVal fdwItalic As Boolean, ByVal fdwUnderline As Boolean, ByVal fdwStrikeOut As Boolean, ByVal fdwCharSet As Long, ByVal fdwOutputPrecision As Long, ByVal fdwClipPrecision As Long, ByVal fdwQuality As Long, ByVal fdwPitchAndFamily As Long, ByVal lpszFace As String) As Long
Private Declare Function SelectObject Lib "gdi32" (ByVal hdc As Long, ByVal hObject As Long) As Long
Private Declare Function TextOut Lib "gdi32" Alias "TextOutA" (ByVal hdc As Long, ByVal x As Long, ByVal y As Long, ByVal lpString As String, ByVal nCount As Long) As Long
Private Declare Function MulDiv Lib "kernel32" (ByVal nNumber As Long, ByVal nNumerator As Long, ByVal nDenominator As Long) As Long
Private Declare Function SetBkMode Lib "gdi32" (ByVal hdc As Long, ByVal nBkMode As Long) As Long
Private Declare Function GetSysColorBrush Lib "user32" (ByVal nIndex As Long) As Long
Private Declare Function FillRect Lib "user32" (ByVal hdc As Long, lpRect As RECT, ByVal hBrush As Long) As Long
Private Declare Function SetRect Lib "user32" (lpRect As RECT, ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long) As Long
Dim mDC As Long, mBitmap As Long
Private Sub Form_Click()
    Unload Me
End Sub
Private Sub Form_Load()
    'KPD-Team 1999
    'URL: http://www.allapi.net/
    'E-Mail: [email protected]
    Dim mRGN As Long, Cnt As Long, mBrush As Long, R As RECT
    'Create a device context, compatible with the screen
    mDC = CreateCompatibleDC(GetDC(0))
    'Create a bitmap, compatible with the screen
    mBitmap = CreateCompatibleBitmap(GetDC(0), Me.Width / Screen.TwipsPerPixelX, Me.Height / Screen.TwipsPerPixelY)
    'Select the bitmap nito the device context
    SelectObject mDC, mBitmap
    'Set the bitmap's backmode to transparent
    SetBkMode mDC, TRANSPARENT
    'Set the rectangles' values
    SetRect R, 0, 0, Me.Width / Screen.TwipsPerPixelX, Me.Height / Screen.TwipsPerPixelY
    'Fill the rect with the default window-color
    FillRect mDC, R, GetSysColorBrush(COLOR_WINDOW)    For Cnt = 0 To 350 Step 30
        'Select the new font into the form's device context and delete the old font
        DeleteObject SelectObject(mDC, CreateMyFont(24, Cnt))
        'Print some text
        TextOut mDC, (Me.Width / Screen.TwipsPerPixelX) / 2, (Me.Height / Screen.TwipsPerPixelY) / 2, Message, Len(Message)
    Next Cnt    'Create an elliptical region
    mRGN = CreateEllipticRgn(0, 0, Me.Width / Screen.TwipsPerPixelX, Me.Height / Screen.TwipsPerPixelY)
    'Set the window region
    SetWindowRgn Me.hWnd, mRGN, True    'delete our elliptical region
    DeleteObject mRGN
End Sub
Function CreateMyFont(nSize As Integer, nDegrees As Long) As Long
    'Create a specified font
    CreateMyFont = CreateFont(-MulDiv(nSize, GetDeviceCaps(GetDC(0), LOGPIXELSY), 72), 0, nDegrees * 10, 0, FW_NORMAL, False, False, False, DEFAULT_CHARSET, OUT_DEFAULT_PRECIS, CLIP_DEFAULT_PRECIS, PROOF_QUALITY, DEFAULT_PITCH, "Times New Roman")
End Function
Private Sub Form_Paint()
    'Copy the picture to the form
    BitBlt Me.hdc, 0, 0, Me.Width / Screen.TwipsPerPixelX, Me.Height / Screen.TwipsPerPixelY, mDC, 0, 0, vbSrcCopy
End Sub
Private Sub Form_Unload(Cancel As Integer)
    'clean up
    DeleteDC mDC
    DeleteObject mBitmap
End Sub
函数说明：【VB声明】
  Private Declare Function BitBlt Lib "gdi32" Alias "BitBlt" (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【说明】
  将一幅位图从一个设备场景复制到另一个。源和目标DC相互间必须兼容【返回值】
  Long，非零表示成功，零表示失败。会设置GetLastError 【备注】
  在NT环境下，如在一次世界传输中要求在源设备场景中进行剪切或旋转处理，这个函数的执行会失败
  如目标和源DC的映射关系要求矩形中像素的大小必须在传输过程中改变，那么这个函数会根据需要自动伸缩、旋转、折叠、或切断，以便完成最终的传输过程【参数表】
  hDestDC --------  Long，目标设备场景  x,y ------------  Long，对目标DC中目标矩形左上角位置进行描述的那个点。用目标DC的逻辑坐标表示  nWidth,nHeight -  Long，欲传输图象的宽度和高度  hSrcDC ---------  Long，源设备场景。如光栅运算未指定源，则应设为0  xSrc,ySrc ------  Long，对源DC中源矩形左上角位置进行描述的那个点。用源DC的逻辑坐标表示  dwRop ----------  Long，传输过程要执行的光栅运算
'建立标准工程，添加一个按钮，一个timer就行了
Option Explicit
Private Declare Function CreateCompatibleBitmap Lib "gdi32" (ByVal hdc As Long, ByVal nWidth As Long, ByVal nHeight As Long) As Long
Private Declare Function CreateCompatibleDC Lib "gdi32" (ByVal hdc As Long) As Long
Private Declare Function SelectObject Lib "gdi32" (ByVal hdc As Long, ByVal hObject As Long) As Long
Private Declare Function CreatePen Lib "gdi32" (ByVal nPenStyle As Long, ByVal nWidth As Long, ByVal crColor As Long) As Long
Private Declare Function DeleteDC Lib "gdi32" (ByVal hdc As Long) As Long
Private Declare Function DeleteObject Lib "gdi32" (ByVal hObject 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 Rectangle Lib "gdi32" (ByVal hdc As Long, ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long) As Long
Private Declare Function Ellipse Lib "gdi32" (ByVal hdc As Long, ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long) As Long
Private Declare Function CreateBrushIndirect Lib "gdi32" (lpLogBrush As LOGBRUSH) As Long
Private Type LOGBRUSH
        lbStyle As Long
        lbColor As Long
        lbHatch As Long
End Type
Private Const PS_SOLID = 0
Private Const SRCCOPY = &HCC0020
Private Const pi = 3.1415926
Private Const BS_SOLID = 0
Dim g__index As Integer
Dim memdc(0 To 40) As Long
Dim membmp(0 To 40) As Long
Dim oldbmp(0 To 40) As Long
Private Sub c_Click()
    If LCase(c.Caption) = "start" Then
        t.Enabled = True
        c.Caption = "stop"
    Else
        t.Enabled = False
        c.Caption = "start"
    End If
End SubPrivate Sub Form_Load()
    c.Caption = "start"
    t.Enabled = False
    t.Interval = 50
    Dim i As Integer
    For i = 0 To 40
        memdc(i) = CreateCompatibleDC(Me.hdc)
        membmp(i) = CreateCompatibleBitmap(Me.hdc, 200, 200)
        oldbmp(i) = SelectObject(memdc(i), membmp(i))
    Next i
    For i = 0 To 40
        draw i, 200, 200
    Next i
End SubPrivate Sub Form_Unload(Cancel As Integer)
    Dim i As Integer
    For i = 0 To 40
        SelectObject memdc(i), oldbmp(i)
        DeleteObject membmp(i)
        DeleteDC memdc(i)
    Next i
End SubPrivate Sub draw(ByVal angle As Integer, ByVal nw As Long, ByVal nh As Long)
    Dim i As Double
    Dim j As Double
    Dim x As Double
    Dim y As Double
    Dim rx As Double
    Dim ry As Double
    Dim r0 As Double
    Dim r1 As Double
    Dim xx As Long
    Dim yy As Long
    rx = nw / 2
    ry = nh / 2
    r0 = 70
    r1 = 20
    Dim hpen As Long
    Dim oldpen As Long
    Dim hbrush As Long
    Dim oldbrush As Long
    Dim log As LOGBRUSH
    log.lbColor = CLng(RGB(0, Abs(angle - 20) * 12, 0))
    log.lbStyle = BS_SOLID
    hbrush = CreateBrushIndirect(log)
    oldbrush = SelectObject(memdc(angle), hbrush)
    Rectangle memdc(angle), 0, 0, nw, nh
    SelectObject memdc(angle), oldbrush
    DeleteObject hbrush
    hpen = CreatePen(PS_SOLID, 1, CLng(RGB(Abs(angle - 20) * 12, 0, Abs(angle - 20) * 12)))
    oldpen = SelectObject(memdc(angle), hpen)
    For i = 0 To 2 * pi Step pi / 4
        For j = 0 To 2 * pi Step pi / 10
            x = rx + r0 * Cos(i + (angle / 40) * 2 * pi)
            y = ry + r0 * Sin(i + (angle / 40) * 2 * pi)
            xx = x + r1 * Cos(j)
            yy = y + r1 * Sin(j)
            Ellipse memdc(angle), xx - 3, yy - 3, xx + 3, yy + 3
        Next j
    Next i
    SelectObject memdc(angle), oldpen
    DeleteObject hpen
End SubPrivate Sub t_Timer()
    BitBlt Me.hdc, 0, 0, 200, 200, memdc(g__index), 0, 0, SRCCOPY
    g__index = g__index + 1
    If g__index > 40 Then
        g__index = 1
    End If
End Sub

调试易

bitblt是api函数，看看它的魅力吧

解决方案 »