利用VB捕捉并保存屏幕图象


		

	

        

 

 

　　大家知道在VB下利用API函数Bitblt可以将屏幕或者窗口上的图象拷贝到VB中的PictureBox对象中,但是如果简单的利用PictureBox的SavePicture函数来保存图象，会发现什么也保存不了。这篇文章就是介绍如何捕获并利用Windows下的OLE API函数保存图象。

　　首先来看源程序，首先建立一个新的工程文件，然后在Form1中加入5个CommandButton对象和一个PictureBox对象，然后在Form1中加入以下代码：

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

End Type

 

Private Type GUID

　 Data1 As Long

　 Data2 As Integer

　 Data3 As Integer

　 Data4(7) As Byte

End Type

 

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

 

捕捉整个屏幕

Private Sub Command1_Click()

　 Set Picture1.Picture = CaptureScreen()

End Sub

&nb

补充：软件开发 , Vb ,