ResizePicturevb.net

Private Function ResizePicture(ByVal objCtrl As Object, ByVal dblWidthRate As Double, ByVal dblHeightRate As Double) As Integer If objCtrl.Image Is Nothing Then Exit Function Dim intWidth%, intHeight% Dim objImg As System.Drawing.Image = objCtrl.Image intWidth = objImg.Width '获得原始image的大小 intHeight = objImg.Height Dim objBmp As New Bitmap(CInt(intWidth * dblWidthRate), CInt(intHeight * dblHeightRate)) '创建画布（画布大小即扩缩后的大小） Dim objG As Graphics = Graphics.FromImage(objBmp) '载入objG的操作画布objBmp objG.Clear(Color.White) '背景设为白色 objG.InterpolationMode = Drawing2D.InterpolationMode.HighQualityBilinear '高质量 objG.DrawImage(objCtrl.Image, New Rectangle(0, 0, CInt(intWidth * dblWidthRate), CInt(intHeight * dblHeightRate))) objCtrl.Image = objBmp End Function