在VB6和VB.NET中进行图象捕获
VB6中进行图象捕获
'----------------------------------------------------------------------------
'
'Author:lihonggen0
'Date:2002-6-19
'功能：抓屏
'----------------------------------------------------------------------------
Private Type POINTAPI
x As Long
y As Long
End Type
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 GetDC Lib "user32" (ByVal hwnd As Long) As Long
Private Declare Function GetCursorPos Lib "user32" (lpPoint As POINTAPI) As Long
Private Declare Function DrawIcon Lib "user32" (ByVal hdc As Long, ByVal x As Long, ByVal y As Long, ByVal hIcon As Long) As Long
Private Declare Function ReleaseDC Lib "user32" (ByVal hwnd As Long, ByVal hdc As Long) As Long
Private Sub Command1_Click()
Dim hdc As Long
Dim sw As Integer
Dim sh As Integer
Dim CurPos As POINTAPI
Dim Cur As Long
Me.Hide
DoEvents
Picture1.AutoRedraw = True
hdc = GetDC(0)
GetCursorPos CurPos
Cur = GetCursor
Picture1.Width = Screen.Width
Picture1.Height = Screen.Height
sw = Screen.Width / Screen.TwipsPerPixelX
sh = Screen.Height / Screen.TwipsPerPixelY
BitBlt Picture1.hdc, 0, 0, sw, sh, hdc, 0, 0, vbSrcCopy
Me.Show
DrawIcon Picture1.hdc, CurPos.x - 10, CurPos.y - 10, Cur
ReleaseDC 0, hdc
Picture1.AutoRedraw = False
End Sub
'参考
'http://support.microsoft.com/?kbid=210108
http://support.microsoft.com/?id=161299
VB.NET中进行图象捕获 ，需要先引用一些API，以下是声明：
Private Declare Function CreateCompatibleDC Lib "GDI32" (ByVal hDC As Integer) As Integer
Private Declare Function CreateCompatibleBitmap Lib "GDI32" (ByVal hDC As Integer, ByVal nWidth As Integer, ByVal nHeight As Integer) As Integer
Private Declare Function SelectObject Lib "GDI32" (ByVal hDC As Integer, ByVal hObject As Integer) As Integer
Private Declare Function BitBlt Lib "GDI32" (ByVal srchDC As Integer, ByVal srcX As Integer, ByVal srcY As Integer, ByVal srcW As Integer, ByVal srcH As Integer, ByVal desthDC As Integer, ByVal destX As Integer, ByVal destY As Integer, ByVal op As Integer) As Integer
Private Declare Function DeleteDC Lib "GDI32" (ByVal hDC As Integer) As Integer
Private Declare Function DeleteObject Lib "GDI32" (ByVal hObj As Integer) As Integer
Declare Function GetDC Lib "user32" Alias "GetDC" (ByVal hwnd As Integer) As Integer
Const SRCCOPY As Integer = &HCC0020
将以下代码添加到Button1_Click事件中：
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim hDC, hMDC As Integer
Dim hBMP, hBMPOld As Integer
Dim sw, sh As Integer
hDC = GetDC(0)
hMDC = CreateCompatibleDC(hDC)
sw = Screen.PrimaryScreen.Bounds.Width
sh = Screen.PrimaryScreen.Bounds.Height
hBMP = CreateCompatibleBitmap(hDC, sw, sh)
hBMPOld = SelectObject(hMDC, hBMP)
BitBlt(hMDC, 0, 0, sw, sh, hDC, 0, 0, SRCCOPY)
hBMP = SelectObject(hMDC, hBMPOld)
PictureBox1.Image = Image.FromHbitmap(New IntPtr(hBMP))
DeleteDC(hDC)
DeleteDC(hMDC)
DeleteObject(hBMP)
End Sub
