form1.frm

大量优秀的vb编程

Public Function CreateBitmapPicture(ByVal hBmp As Long, ByVal hPal As Long) As Picture
  Dim r As Long

   Dim Pic As PicBmp
   ' IPicture requires a reference to "Standard OLE Types."
   Dim IPic As IPicture
   Dim IID_IDispatch As GUID

   ' Fill in with IDispatch Interface ID.
   With IID_IDispatch
      .Data1 = &H20400
      .Data4(0) = &HC0
      .Data4(7) = &H46
   End With

   ' Fill Pic with necessary parts.
   With Pic
      .Size = Len(Pic)          ' Length of structure.
      .Type = vbPicTypeBitmap   ' Type of Picture (bitmap).
      .hBmp = hBmp              ' Handle to bitmap.
      .hPal = hPal              ' Handle to palette (may be null).
   End With

   ' Create Picture object.
   r = OleCreatePictureIndirect(Pic, IID_IDispatch, 1, IPic)

   ' Return the new Picture object.
   Set CreateBitmapPicture = IPic
End Function

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'
' CaptureWindow
'    - Captures any portion of a window.
'
' hWndSrc
'    - Handle to the window to be captured.
'
' Client
'    - If True CaptureWindow captures from the client area of the
'      window.
'    - If False CaptureWindow captures from the entire window.
'
' LeftSrc, TopSrc, WidthSrc, HeightSrc
'    - Specify the portion of the window to capture.
'    - Dimensions need to be specified in pixels.
'
' Returns
'    - Returns a Picture object containing a bitmap of the specified
'      portion of the window that was captured.
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''''''
'

  Public Function CaptureWindow(ByVal hWndSrc As Long, ByVal Client As Boolean, ByVal LeftSrc As Long, ByVal TopSrc As Long, ByVal WidthSrc As Long, ByVal HeightSrc As Long) As Picture

  Dim hDCMemory As Long
  Dim hBmp As Long
  Dim hBmpPrev As Long
  Dim r As Long
  Dim hDCSrc As Long
  Dim hPal As Long
  Dim hPalPrev As Long
  Dim RasterCapsScrn As Long
  Dim HasPaletteScrn As Long
  Dim PaletteSizeScrn As Long
  Dim LogPal As LOGPALETTE

   ' Depending on the value of Client get the proper device context.
   If Client Then
      hDCSrc = GetDC(hWndSrc) ' Get device context for client area.
   Else
      hDCSrc = GetWindowDC(hWndSrc) ' Get device context for entire
                                    ' window.
   End If

   ' Create a memory device context for the copy process.
   hDCMemory = CreateCompatibleDC(hDCSrc)
   ' Create a bitmap and place it in the memory DC.
   hBmp = CreateCompatibleBitmap(hDCSrc, WidthSrc, HeightSrc)
   hBmpPrev = SelectObject(hDCMemory, hBmp)

   ' Get screen properties.
   RasterCapsScrn = GetDeviceCaps(hDCSrc, RASTERCAPS) ' Raster
                                                      ' capabilities.
   HasPaletteScrn = RasterCapsScrn And RC_PALETTE       ' Palette
                                                        ' support.
   PaletteSizeScrn = GetDeviceCaps(hDCSrc, SIZEPALETTE) ' Size of
                                                        ' palette.

   ' If the screen has a palette make a copy and realize it.
   If HasPaletteScrn And (PaletteSizeScrn = 256) Then
      ' Create a copy of the system palette.
      LogPal.palVersion = &H300
      LogPal.palNumEntries = 256
      r = GetSystemPaletteEntries(hDCSrc, 0, 256, LogPal.palPalEntry(0))
      hPal = CreatePalette(LogPal)
      ' Select the new palette into the memory DC and realize it.
      hPalPrev = SelectPalette(hDCMemory, hPal, 0)
      r = RealizePalette(hDCMemory)
   End If

   ' Copy the on-screen image into the memory DC.
   r = BitBlt(hDCMemory, 0, 0, WidthSrc, HeightSrc, hDCSrc, LeftSrc, TopSrc, vbSrcCopy)

' Remove the new copy of the  on-screen image.
   hBmp = SelectObject(hDCMemory, hBmpPrev)

   ' If the screen has a palette get back the palette that was
   ' selected in previously.
   If HasPaletteScrn And (PaletteSizeScrn = 256) Then
      hPal = SelectPalette(hDCMemory, hPalPrev, 0)
   End If

   ' Release the device context resources back to the system.
   r = DeleteDC(hDCMemory)
   r = ReleaseDC(hWndSrc, hDCSrc)

   ' Call CreateBitmapPicture to create a picture object from the
   ' bitmap and palette handles. Then return the resulting picture
   ' object.
   Set CaptureWindow = CreateBitmapPicture(hBmp, hPal)
End Function

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'
' CaptureScreen
'    - Captures the entire screen.
'
' Returns
'    - Returns a Picture object containing a bitmap of the screen.
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'
Public Function CaptureScreen() As Picture
  Dim hWndScreen As Long

   ' Get a handle to the desktop window.
   hWndScreen = GetDesktopWindow()

   ' Call CaptureWindow to capture the entire desktop give the handle
   ' and return the resulting Picture object.

   Set CaptureScreen = CaptureWindow(hWndScreen, False, 0, 0, Screen.Width \ Screen.TwipsPerPixelX, Screen.Height \ Screen.TwipsPerPixelY)
End Function

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'
' CaptureForm
'    - Captures an entire form including title bar and border.
'
' frmSrc
'    - The Form object to capture.
'
' Returns
'    - Returns a Picture object containing a bitmap of the entire
'      form.
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'
Public Function CaptureForm(frmSrc As Form) As Picture
   ' Call CaptureWindow to capture the entire form given its window
   ' handle and then return the resulting Picture object.
   Set CaptureForm = CaptureWindow(frmSrc.hWnd, False, 0, 0, frmSrc.ScaleX(frmSrc.Width, vbTwips, vbPixels), frmSrc.ScaleY(frmSrc.Height, vbTwips, vbPixels))
End Function

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'
' CaptureClient
'    - Captures the client area of a form.
'
' frmSrc
'    - The Form object to capture.
'
' Returns
'    - Returns a Picture object containing a bitmap of the form's
'      client area.
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'
Public Function CaptureClient(frmSrc As Form) As Picture
   ' Call CaptureWindow to capture the client area of the form given
   ' its window handle and return the resulting Picture object.
   Set CaptureClient = CaptureWindow(frmSrc.hWnd, True, 0, 0, frmSrc.ScaleX(frmSrc.ScaleWidth, frmSrc.ScaleMode, vbPixels), frmSrc.ScaleY(frmSrc.ScaleHeight, frmSrc.ScaleMode, vbPixels))
End Function

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'
' CaptureActiveWindow
'    - Captures the currently active window on the screen.
'
' Returns
'    - Returns a Picture object containing a bitmap of the active
'      window.
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'
Public Function CaptureActiveWindow() As Picture

    Dim hWndActive As Long
    Dim r As Long
    
    Dim RectActive As RECT
    
    ' Get a handle to the active/foreground window.
    hWndActive = GetForegroundWindow()
    
    ' Get the dimensions of the window.
    r = GetWindowRect(hWndActive, RectActive)
    
    ' Call CaptureWindow to capture the active window given its
    ' handle and return the Resulting Picture object.
    Set CaptureActiveWindow = CaptureWindow(hWndActive, False, 0, 0, RectActive.Right - RectActive.Left, RectActive.Bottom - RectActive.Top)
End Function

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'
' PrintPictureToFitPage
'    - Prints a Picture object as big as possible.
'
' Prn
'    - Destination Printer object.
'
' Pic
'    - Source Picture object.
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'
Public Sub PrintPictureToFitPage(Prn As Printer, Pic As Picture)
    
    Const vbHiMetric As Integer = 8
    Dim PicRatio As Double
    Dim PrnWidth As Double
    Dim PrnHeight As Double
    Dim PrnRatio As Double
    Dim PrnPicWidth As Double
    Dim PrnPicHeight As Double
    
    ' Determine if picture should be printed in landscape or portrait
    ' and set the orientation.
    If Pic.Height >= Pic.Width Then
        Prn.Orientation = vbPRORPortrait   ' Taller than wide.
    Else
        Prn.Orientation = vbPRORLandscape  ' Wider than tall.
    End If
    
    ' Calculate device independent Width-to-Height ratio for picture.
    PicRatio = Pic.Width / Pic.Height
    
    ' Calculate the dimentions of the printable area in HiMetric.
    PrnWidth = Prn.ScaleX(Prn.ScaleWidth, Prn.ScaleMode, vbHiMetric)
    PrnHeight = Prn.ScaleY(Prn.ScaleHeight, Prn.ScaleMode, vbHiMetric)
    ' Calculate device independent Width to Height ratio for printer.
    PrnRatio = PrnWidth / PrnHeight
    
    ' Scale the output to the printable area.
    If PicRatio >= PrnRatio Then
        ' Scale picture to fit full width of printable area.
        PrnPicWidth = Prn.ScaleX(PrnWidth, vbHiMetric, Prn.ScaleMode)
        PrnPicHeight = Prn.ScaleY(PrnWidth / PicRatio, vbHiMetric, Prn.ScaleMode)
    Else
        ' Scale picture to fit full height of printable area.
        PrnPicHeight = Prn.ScaleY(PrnHeight, vbHiMetric, Prn.ScaleMode)
        PrnPicWidth = Prn.ScaleX(PrnHeight * PicRatio, vbHiMetric, Prn.ScaleMode)
    End If
    
    ' Print the picture using the PaintPicture method.
    Prn.PaintPicture Pic, 0, 0, PrnPicWidth, PrnPicHeight
End Sub
'-------------------------------------------------------------------


Private Sub Command7_Click()

CommonDialog1.DefaultExt = ".BMP"
CommonDialog1.Filter = "Bitmap Image (*.bmp)|*.bmp"
CommonDialog1.ShowSave
If CommonDialog1.FileName <> "" Then
    SavePicture Picture1.Picture, CommonDialog1.FileName
End If

End Sub