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1. Start a
new project. Form1 is created by default.
2. Place six CommandButtons on the form
along the left side.
3. Place one picture box on the form to
the right of the buttons.
4. Put the following code in 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. Add a new standard module to the
project (module1 by default).
6. Put the following code in the new
module:
'--------------------------------------------------------------------
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'
' 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 it's 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
' it's 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 it's
' 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
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