Artigo: 161299 - Última revisão: quinta-feira, 15 de Julho de 2004 - Revisão: 3.3

Como capturar e o ecrã, um formulário ou qualquer janela de impressão

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Sumário

Este artigo mostra como capturar qualquer formulário ou janela incluindo o ecrã para um objecto de imagem do Visual Basic. Uma vez a imagem é capturada no objecto de imagem no ecrã, facilmente podem ser impressas utilizando o método PaintPicture do objecto de impressora do Visual Basic.

Mais Informação

O exemplo incluído fornece várias rotinas útil para capturar imagens. Todas as rotinas foram escritas para trabalhar em ambas as 16 e 32 bits plataformas do Windows e podem conter suporte paleta completo. As rotinas no exemplo que podem:
  • Capture todo o conteúdo de um formulário.
  • Capture a área cliente de um formulário.
  • Capture o ecrã inteiro.
  • Capture a janela activa no ecrã.
  • Capture qualquer parte de qualquer janela atribuída um identificador.
  • Crie um objecto imagem a partir de um mapa de bits e uma paleta.
  • Imprimir um objecto de imagem tão grande quanto possível na página.
Visual Basic 4.0 apresentou um novo objecto de imagem. O objecto de imagem é realmente um tipo OLE padrão e é documentada no controlo Developer Kit (CDK.)

O CDK inclui a função OleCreatePictureIndirect que pode utilizar para criar novos objectos de imagem a partir do Visual Basic 4.0. A rotina CreateBitmapPicture no exemplo chama OleCreatePictureIndirect para criar um objecto de imagem de um identificador para um mapa de bits e um identificador para uma paleta. Se a imagem inclui uma paleta válida, do Visual Basic saberá utilizá-lo durante a composição de imagem para o ecrã ou impressora. A rotina CreateBitmapPicture é utilizada pela rotina CaptureWindow para criar objectos de imagem que contém um mapa de bits de uma parte ou todos de uma janela.

A rotina CaptureWindow no exemplo captura qualquer parte de uma janela atribuída um identificador de janela. A rotina inclui vários parâmetros para descrever a parte da janela para capturar exacta. Capturar janela funciona, copiando o ecrã imagem de uma janela para um novo mapa de bits. Também verifica se o ecrã tem uma paleta e caso efectua uma cópia da mesma. CaptureWindow, em seguida, chama CreateBitmapPicture para construir um mapa de bits do mapa de bits criado recentemente e paleta.

As rotinas CaptureForm, CaptureClient, CaptureScreen e CaptureActiveWindow incluídas no exemplo todos os utilizar CaptureWindow para capturar windows específicos. CaptureForm CaptureClient tanto chamar janela de captura e transmiti-las a propriedade hWnd de um objecto de formulário. CaptureScreen simplesmente obtém o identificador para a janela do ambiente de trabalho e chama CaptureWindow. Do mesmo modo, CaptureActiveWindow apenas obtém o identificador de janela da janela activa e chama CaptureWindow.

Depois da imagem pretendida for capturada num objecto de imagem, é fácil imprimir no Visual Basic 4.0 utilizando o método PaintPicture do objecto de impressora. O exemplo fornece a rotina PrintPictureToFitPage que utiliza o PaintPictureMethod para imprimir as imagens capturadas tão grande quanto possível na área de impressão da página.

Exemplo

  1. Inicie um novo projecto. É criado o Form1 por predefinição.
  2. Coloque seis CommandButtons no formulário ao longo do lado esquerdo.
  3. Coloque uma caixa de imagem no formulário para a direita dos botões.
  4. Coloque o código seguinte no Form1:
          '--------------------------------------------------------------------
          ' Capture the entire screen.
    
          Private Sub Command1_Click()
             Set Picture1.Picture = CaptureScreen()
          End Sub
    
          ' Capture the entire form including title and border.
          Private Sub Command2_Click()
             Set Picture1.Picture = CaptureForm(Me)
          End Sub
    
          ' Capture the client area of the form.
          Private Sub Command3_Click()
             Set Picture1.Picture = CaptureClient(Me)
          End Sub
    
          ' Capture the active window after two seconds.
          Private Sub Command4_Click()
             MsgBox "Two seconds after you close this dialog " & _
                "the active window will be captured."
    
             ' Wait for two seconds.
             Dim EndTime As Date
             EndTime = DateAdd("s", 2, Now)
             Do Until Now > EndTime
                DoEvents
             Loop
    
             Set Picture1.Picture = CaptureActiveWindow()
    
             ' Set focus back to form.
             Me.SetFocus
          End Sub
    
          ' Print the current contents of the picture box.
          Private Sub Command5_Click()
             PrintPictureToFitPage Printer, Picture1.Picture
             Printer.EndDoc
          End Sub
    
          ' Clear out the picture box.
          Private Sub Command6_Click()
             Set Picture1.Picture = Nothing
          End Sub
    
          ' Initialize the form and controls.
          Private Sub Form_Load()
             Me.Caption = "Capture and Print Example"
             Command1.Caption = "&Screen"
             Command2.Caption = "&Form"
             Command3.Caption = "&Client"
             Command4.Caption = "&Active"
             Command5.Caption = "&Print"
             Command6.Caption = "C&lear"
             Picture1.AutoSize = True
          End Sub
          '--------------------------------------------------------------------
    
    					
  5. Adicione um novo módulo padrão ao projecto (module1 por predefinição).
  6. Coloque o seguinte código no novo módulo:
          '--------------------------------------------------------------------
          '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
          '
          ' Visual Basic 4.0 16/32 Capture Routines
          '
          ' This module contains several routines for capturing windows into a
          ' picture.  All the routines work on both 16 and 32 bit Windows
          ' platforms.
          ' The routines also have palette support.
          '
          ' CreateBitmapPicture - Creates a picture object from a bitmap and
          ' palette.
          ' CaptureWindow - Captures any window given a window handle.
          ' CaptureActiveWindow - Captures the active window on the desktop.
          ' CaptureForm - Captures the entire form.
          ' CaptureClient - Captures the client area of a form.
          ' CaptureScreen - Captures the entire screen.
          ' PrintPictureToFitPage - prints any picture as big as possible on
          ' the page.
          '
          ' NOTES
          '    - No error trapping is included in these routines.
          '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
          '
          Option Explicit
          Option Base 0
    
          Private Type PALETTEENTRY
             peRed As Byte
             peGreen As Byte
             peBlue As Byte
             peFlags As Byte
          End Type
    
          Private Type LOGPALETTE
             palVersion As Integer
             palNumEntries As Integer
             palPalEntry(255) As PALETTEENTRY  ' Enough for 256 colors.
          End Type
    
          Private Type GUID
             Data1 As Long
             Data2 As Integer
             Data3 As Integer
             Data4(7) As Byte
          End Type
    
          #If Win32 Then
    
             Private Const RASTERCAPS As Long = 38
             Private Const RC_PALETTE As Long = &H100
             Private Const SIZEPALETTE As Long = 104
    
             Private Type RECT
                Left As Long
                Top As Long
                Right As Long
                Bottom As Long
             End Type
    
             Private Declare Function CreateCompatibleDC Lib "GDI32" ( _
                ByVal hDC 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 GetDeviceCaps Lib "GDI32" ( _
                ByVal hDC As Long, ByVal iCapabilitiy As Long) As Long
             Private Declare Function GetSystemPaletteEntries Lib "GDI32" ( _
                ByVal hDC As Long, ByVal wStartIndex As Long, _
                ByVal wNumEntries As Long, lpPaletteEntries As PALETTEENTRY) _
                As Long
             Private Declare Function CreatePalette Lib "GDI32" ( _
                lpLogPalette As LOGPALETTE) As Long
             Private Declare Function SelectObject Lib "GDI32" ( _
                ByVal hDC As Long, ByVal hObject As Long) As Long
             Private Declare Function BitBlt Lib "GDI32" ( _
                ByVal hDCDest As Long, ByVal XDest As Long, _
                ByVal YDest As Long, ByVal nWidth As Long, _
                ByVal nHeight As Long, ByVal hDCSrc As Long, _
                ByVal XSrc As Long, ByVal YSrc As Long, ByVal dwRop As Long) _
                As Long
             Private Declare Function DeleteDC Lib "GDI32" ( _
                ByVal hDC As Long) As Long
             Private Declare Function GetForegroundWindow Lib "USER32" () _
                As Long
             Private Declare Function SelectPalette Lib "GDI32" ( _
                ByVal hDC As Long, ByVal hPalette As Long, _
                ByVal bForceBackground As Long) As Long
             Private Declare Function RealizePalette Lib "GDI32" ( _
                ByVal hDC As Long) As Long
             Private Declare Function GetWindowDC Lib "USER32" ( _
                ByVal hWnd As Long) As Long
             Private Declare Function GetDC Lib "USER32" ( _
                ByVal hWnd As Long) As Long
             Private Declare Function GetWindowRect Lib "USER32" ( _
                ByVal hWnd As Long, lpRect As RECT) As Long
             Private Declare Function ReleaseDC Lib "USER32" ( _
                ByVal hWnd As Long, ByVal hDC As Long) As Long
             Private Declare Function GetDesktopWindow Lib "USER32" () As Long
    
             Private Type PicBmp
                Size As Long
                Type As Long
                hBmp As Long
                hPal As Long
                Reserved As Long
             End Type
    
             Private Declare Function OleCreatePictureIndirect _
                Lib "olepro32.dll" ( PicDesc As PicBmp, RefIID As GUID, _
                ByVal fPictureOwnsHandle As Long, IPic As IPicture) As Long
    
          #ElseIf Win16 Then
    
             Private Const RASTERCAPS As Integer = 38
             Private Const RC_PALETTE As Integer = &H100
             Private Const SIZEPALETTE As Integer = 104
    
             Private Type RECT
                Left As Integer
                Top As Integer
                Right As Integer
                Bottom As Integer
             End Type
    
             Private Declare Function CreateCompatibleDC Lib "GDI" ( _
                ByVal hDC As Integer) As Integer
             Private Declare Function CreateCompatibleBitmap Lib "GDI" ( _
                ByVal hDC As Integer, ByVal nWidth As Integer, _
                ByVal nHeight As Integer) As Integer
             Private Declare Function GetDeviceCaps Lib "GDI" ( _
                ByVal hDC As Integer, ByVal iCapabilitiy As Integer) As Integer
             Private Declare Function GetSystemPaletteEntries Lib "GDI" ( _
                ByVal hDC As Integer, ByVal wStartIndex As Integer, _
                ByVal wNumEntries As Integer, _
                lpPaletteEntries As PALETTEENTRY) As Integer
             Private Declare Function CreatePalette Lib "GDI" ( _
                lpLogPalette As LOGPALETTE) As Integer
             Private Declare Function SelectObject Lib "GDI" ( _
                ByVal hDC As Integer, ByVal hObject As Integer) As Integer
             Private Declare Function BitBlt Lib "GDI" ( _
                ByVal hDCDest As Integer, ByVal XDest As Integer, _
                ByVal YDest As Integer, ByVal nWidth As Integer, _
                ByVal nHeight As Integer, ByVal hDCSrc As Integer, _
                ByVal XSrc As Integer, ByVal YSrc As Integer, _
                ByVal dwRop As Long) As Integer
             Private Declare Function DeleteDC Lib "GDI" ( _
                ByVal hDC As Integer) As Integer
             Private Declare Function GetForegroundWindow Lib "USER" _
                Alias "GetActiveWindow" () As Integer
             Private Declare Function SelectPalette Lib "USER" ( _
                ByVal hDC As Integer, ByVal hPalette As Integer, ByVal _
                bForceBackground As Integer) As Integer
             Private Declare Function RealizePalette Lib "USER" ( _
                ByVal hDC As Integer) As Integer
             Private Declare Function GetWindowDC Lib "USER" ( _
                ByVal hWnd As Integer) As Integer
             Private Declare Function GetDC Lib "USER" ( _
                ByVal hWnd As Integer) As Integer
             Private Declare Function GetWindowRect Lib "USER" ( _
                ByVal hWnd As Integer, lpRect As RECT) As Integer
             Private Declare Function ReleaseDC Lib "USER" ( _
                ByVal hWnd As Integer, ByVal hDC As Integer) As Integer
             Private Declare Function GetDesktopWindow Lib "USER" () As Integer
    
             Private Type PicBmp
                Size As Integer
                Type As Integer
                hBmp As Integer
                hPal As Integer
                Reserved As Integer
             End Type
    
             Private Declare Function OleCreatePictureIndirect _
                Lib "oc25.dll" ( PictDesc As PicBmp, RefIID As GUID, _
                ByVal fPictureOwnsHandle As Integer, IPic As IPicture) _
                As Integer
    
          #End If
    
          '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
          '
          ' CreateBitmapPicture
          '    - Creates a bitmap type Picture object from a bitmap and
          '      palette.
          '
          ' hBmp
          '    - Handle to a bitmap.
          '
          ' hPal
          '    - Handle to a Palette.
          '    - Can be null if the bitmap doesn't use a palette.
          '
          ' Returns
          '    - Returns a Picture object containing the bitmap.
          '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
          '
          #If Win32 Then
             Public Function CreateBitmapPicture(ByVal hBmp As Long, _
                ByVal hPal As Long) As Picture
    
                Dim r As Long
          #ElseIf Win16 Then
             Public Function CreateBitmapPicture(ByVal hBmp As Integer, _
                ByVal hPal As Integer) As Picture
    
                Dim r As Integer
          #End If
             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
    
          '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
          '
          ' 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.
          '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
          ''''''
          '
          #If Win32 Then
             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
          #ElseIf Win16 Then
             Public Function CaptureWindow(ByVal hWndSrc As Integer, _
                ByVal Client As Boolean, ByVal LeftSrc As Integer, _
                ByVal TopSrc As Integer, ByVal WidthSrc As Long, _
                ByVal HeightSrc As Long) As Picture
    
                Dim hDCMemory As Integer
                Dim hBmp As Integer
                Dim hBmpPrev As Integer
                Dim r As Integer
                Dim hDCSrc As Integer
                Dim hPal As Integer
                Dim hPalPrev As Integer
                Dim RasterCapsScrn As Integer
                Dim HasPaletteScrn As Integer
                Dim PaletteSizeScrn As Integer
          #End If
             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
    
          '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
          '
          ' CaptureScreen
          '    - Captures the entire screen.
          '
          ' Returns
          '    - Returns a Picture object containing a bitmap of the screen.
          '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
          '
          Public Function CaptureScreen() As Picture
             #If Win32 Then
                Dim hWndScreen As Long
             #ElseIf Win16 Then
                Dim hWndScreen As Integer
             #End If
    
             ' 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
    
          '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
          '
          ' 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.
          '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
          '
          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
    
          '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
          '
          ' 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.
          '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
          '
          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
    
          '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
          '
          ' CaptureActiveWindow
          '    - Captures the currently active window on the screen.
          '
          ' Returns
          '    - Returns a Picture object containing a bitmap of the active
          '      window.
          '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
          '
          Public Function CaptureActiveWindow() As Picture
             #If Win32 Then
                Dim hWndActive As Long
                Dim r As Long
             #ElseIf Win16 Then
                Dim hWndActive As Integer
                Dim r As Integer
             #End If
             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
    
          '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
          '
          ' PrintPictureToFitPage
          '    - Prints a Picture object as big as possible.
          '
          ' Prn
          '    - Destination Printer object.
          '
          ' Pic
          '    - Source Picture object.
          '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
          '
          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
          '--------------------------------------------------------------------
    					
  7. Guarde o projecto.
  8. Antes de executar este projecto no, verifique se Project References existência uma referência a Automação OLE (StdOle2.tlb).
  9. Execute o projecto e teste. Poderá capturar o formulário, área de cliente do formulário, o ecrã e a janela activa. Poderá também imprimir qualquer um destes itens.
NOTA: Uma vez capturadas a imagem que pretende num objecto de imagem, pode facilmente colocá-lo na área de transferência utilizando o método SetData do objecto da área de transferência.

Referências

Para obter informações adicionais, clique nos números de artigo existentes abaixo para visualizar os artigos na Microsoft Knowledge Base:
230502  (http://support.microsoft.com/kb/230502/EN-US/ ) Como imprimir um formulário que é demasiado grande para o ecrã ou página
178076  (http://support.microsoft.com/kb/178076/EN-US/ ) Como utilizar uma PictureBox a orientação do controlo de impressão de um formulário
194580  (http://support.microsoft.com/kb/194580/EN-US/ ) Como imprimir uma imagem composta de um RichTextBox
146022  (http://support.microsoft.com/kb/146022/EN-US/ ) Como configurar o controlo RichTextBox para impressão WYSIWYG

A informação contida neste artigo aplica-se a:
  • Microsoft Visual Basic 5.0 Learning Edition
  • Microsoft Visual Basic 6.0 Learning Edition
  • Microsoft Visual Basic 5.0 Professional Edition
  • Microsoft Visual Basic 6.0 Professional Edition
  • Microsoft Visual Basic 5.0 Enterprise Edition
  • Microsoft Visual Basic Enterprise Edition for Windows 6.0
  • Microsoft Visual Basic 4.0 Professional Edition
  • Microsoft Visual Basic 4.0 Professional Edition
  • Microsoft Visual Basic 4.0 16-bit Enterprise Edition
  • Microsoft Visual Basic 4.0 32-Bit Enterprise Edition
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IMPORTANTE: Este artigo foi traduzido por um sistema de tradução automática (também designado por Machine translation ou MT), não tendo sido portanto revisto ou traduzido por humanos. A Microsoft tem artigos traduzidos por aplicações (MT) e artigos traduzidos por tradutores profissionais. O objectivo é simples: oferecer em Português a totalidade dos artigos existentes na base de dados do suporte. Sabemos no entanto que a tradução automática não é sempre perfeita. Esta pode conter erros de vocabulário, sintaxe ou gramática? erros semelhantes aos que um estrangeiro realiza ao falar em Português. A Microsoft não é responsável por incoerências, erros ou estragos realizados na sequência da utilização dos artigos MT por parte dos nossos clientes. A Microsoft realiza actualizações frequentes ao software de tradução automática (MT). Obrigado.
Clique aqui para ver a versão em Inglês deste artigo: 161299  (http://support.microsoft.com/kb/161299/en-us/ )