GDI+ 图像剪切

 Dim SourceImg As System.Drawing.Image = System.Drawing.Image.FromStream(Me.FileUpload1.PostedFile.InputStream)
        Dim SourceImgWidth As Integer = SourceImg.Width '图片的原始Width 
        Dim SourceImgHeight As Integer = SourceImg.Height '图片的原始Height 

        Dim bit As New Bitmap(SourceImg)


        Dim rec As New Rectangle() '构造一个Rectangle类,一个矩形 
        rec.Width = 100 'ConfigHelper.UserFaceWidth
        rec.Height = 100 'ConfigHelper.UserFaceHeight

        If SourceImgWidth > rec.Width Then
            rec.X = 20 '(SourceImgWidth - rec.Width) / 2
        Else
            rec.X = 0
            rec.Width = SourceImg.Width
        End If

        If SourceImgHeight > rec.Height Then
            rec.Y = 20 '(SourceImgHeight - rec.Height) / 2
        Else
            rec.Y = 0
            rec.Height = SourceImg.Height
        End If

        Try
            '这里就是把从上传过程中构造的bitmap克隆一份,并按定义好的矩形裁剪 
            bit.Clone(rec, PixelFormat.DontCare).Save(Response.OutputStream, ImageFormat.Jpeg)

        Catch ex As Exception
            Context.Response.Write(ex.Message)
            Exit Sub
        Finally
            bit.Dispose()
            SourceImg.Dispose()
        End Try

转载于:https://www.cnblogs.com/yanglin/archive/2007/06/28/799200.html