API函数声明：
Module APIModule APIVB.Net快速移动图像的实例
Declare Function CreateCompatibleDC()Function CreateCompatibleDC Lib "gdi32.dll" (ByVal hdc As IntPtr) As IntPtr Declare Function SelectObject()Function SelectObject Lib "gdi32.dll" (ByVal hdc As IntPtr, ByVal hgdiobj As IntPtr) As IntPtr Declare Function ReleaseDC()Function ReleaseDC Lib "gdi32.dll" (ByVal hWnd As IntPtr, ByVal hDC As IntPtr) As Integer Declare Function GetStretchBltMode()Function GetStretchBltMode Lib "gdi32.dll" (ByVal hdc As IntPtr) As Integer Declare Function SetStretchBltMode()Function SetStretchBltMode Lib "gdi32" (ByVal hdc As IntPtr, ByVal iStretchMode As Integer) As Integer Declare Function DeleteObject()Function DeleteObject Lib "gdi32.dll" (ByVal hObject As IntPtr) As IntPtr Declare Function DeleteDC()Function DeleteDC Lib "gdi32.dll" (ByVal hDc As IntPtr) As IntPtr
Declare Function BitBlt()Function BitBlt Lib "GDI32.DLL" ( _ ByVal hdcDest As IntPtr, _ ByVal nXDest As Integer, _ ByVal nYDest As Integer, _ ByVal nWidth As Integer, _ ByVal nHeight As Integer, _ ByVal hdcSrc As IntPtr, _ ByVal nXSrc As Integer, _ ByVal nYSrc As Integer, _ ByVal dwRop As TernaryRasterOperations) As Boolean Declare Function StretchBlt()Function StretchBlt Lib "gdi32.dll" ( _ ByVal hdcDest As IntPtr, _ ByVal nXOriginDest As Integer, _ ByVal nYOriginDest As Integer, _ ByVal nWidthDest As Integer, _ ByVal nHeightDest As Integer, _ ByVal hdcSrc As IntPtr, _ ByVal nXOriginSrc As Integer, _ ByVal nYOriginSrc As Integer, _ ByVal nWidthSrc As Integer, _ ByVal nHeightSrc As Integer, _ ByVal dwRop As TernaryRasterOperations) As Boolean Enum TernaryRasterOperationsEnum TernaryRasterOperations As Integer SRCCOPY = &HCC0020 SRCPAINT = 15597702 'dest = source OR dest SRCAND = 8913094 'dest = source AND dest SRCINVERT = 6684742 'dest = source XOR dest SRCERASE = 4457256 'dest = source AND (NOT dest ) NOTSRCCOPY = 3342344 'dest = (NOT source) NOTSRCERASE = 1114278 'dest = (NOT src) AND (NOT dest) MERGECOPY = 12583114 'dest = (source AND pattern) MERGEPAINT = 12255782 'dest = (NOT source) OR dest PATCOPY = 15728673 'dest = pattern PATPAINT = 16452105 'dest = DPSnoo PATINVERT = 5898313 'dest = pattern XOR dest DSTINVERT = 5570569 'dest = (NOT dest) BLACKNESS = 66 'dest = BLACK WHITENESS = 16711778 'dest = WHITE
End Enum
End Module
Public Class Form1Class Form1 Dim offset As Point Dim MousePressPoint As Point Dim Gr As Graphics Dim srcBitmap As Bitmap Dim srcHDC, desHDC As IntPtrVB.Net快速移动图像的实例 Dim HBitmapSrc As IntPtr Private Sub Panel1_DoubleClick()Sub Panel1_DoubleClick(ByVal sender As Object, ByVal e As System.EventArgs) Handles Panel1.DoubleClick Dim cd As New OpenFileDialog cd.Filter = "bmp文件 (*.bmp)|*.bmp|jpg文件 (*.jpg)|*.jpg|gif文件 (*.gif)|*.gif|所有文件|*.*" If cd.ShowDialog = Windows.Forms.DialogResult.OK Then srcBitmap = New Bitmap(cd.FileName) offset = New Point(0, 0) Panel1.Invalidate() End If End Sub Private Sub PictureBox1_MouseDown()Sub PictureBox1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Panel1.MouseDown MousePressPoint = e.Location End Sub Private Sub PictureBox1_MouseMove()Sub PictureBox1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Panel1.MouseMove If e.Button = Windows.Forms.MouseButtons.Left Then Windows.Forms.Cursor.Current = Cursors.Hand offset.X += e.X - MousePressPoint.X offset.Y += e.Y - MousePressPoint.Y MousePressPoint = e.Location Call Me.MyReDraw(offset.X, offset.Y) End If End Sub Private Sub PictureBox1_Paint()Sub PictureBox1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Panel1.Paint Call Me.MyReDraw(offset.X, offset.Y) End Sub Sub MyReDraw()Sub MyReDraw(ByVal x As Integer, ByVal y As Integer) If srcBitmap Is Nothing Then Exit Sub If srcHDC.Equals(IntPtr.Zero) Then srcHDC = CreateCompatibleDC(IntPtr.Zero) HBitmapSrc = srcBitmap.GetHbitmap() SelectObject(srcHDC, HBitmapSrc) End If If desHDC.Equals(IntPtr.Zero) Then If IsNothing(Gr) Then Gr = Panel1.CreateGraphics desHDC = Gr.GetHdc() 'SetStretchBltMode(desHDC, 3) End If Call BitBlt(desHDC, 0, 0, Panel1.ClientSize.Width, Panel1.ClientSize.Height, srcHDC, -x, -y, TernaryRasterOperations.SRCCOPY) Gr.ReleaseHdc(desHDC) desHDC = Nothing End Sub Private Sub Form1_FormClosing()Sub Form1_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing If Not IsNothing(srcBitmap) Then srcBitmap.Dispose() If Not srcHDC.Equals(IntPtr.Zero) Then DeleteDC(srcHDC) If Not desHDC.Equals(IntPtr.Zero) Then DeleteDC(desHDC) If Not HBitmapSrc.Equals(IntPtr.Zero) Then DeleteObject(HBitmapSrc) If Not IsNothing(Gr) Then Gr.Dispose() GC.Collect() End SubVB.Net快速移动图像的实例End Class
