打印指定的区域

public void PrintToGraphics(Graphics graphics, Rectangle bounds)
        {
            Bitmap bitmap = new Bitmap(this.Width, this.Height);
            this.DrawToBitmap(bitmap, new Rectangle(0, 0, bitmap.Width, bitmap.Height));
            Rectangle target = new Rectangle(0, 0, bounds.Width, bounds.Height);
            double xScale = (double)bitmap.Width / bounds.Width;
            double yScale = (double)bitmap.Height / bounds.Height;
            if (xScale < yScale)
                target.Width = (int)(xScale * target.Width / yScale);
            else
                target.Height = (int)(yScale * target.Height / xScale);
            graphics.PageUnit = GraphicsUnit.Display;
            graphics.DrawImage(bitmap, target);
        }

        private void printDocument1_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)
        {
            PrintToGraphics(e.Graphics, e.MarginBounds);
        }

        private void button2_Click(object sender, EventArgs e)
        {
            this.printDocument1.Print();
        }