【求帮助！！】用下列代码打印C#Winform界面，如何按照所选纸张大小，让内容能全部打印出来？因为全屏的话，默认的A4纸打不完整。要压缩吗?求高手指导！！

        private Bitmap memoryImage;
        [System.Runtime.InteropServices.DllImport("gdi32.dll")]
        public static extern long BitBlt(IntPtr hdcDest, int nXDest, int nYDest, int nWidth, int nHeight, IntPtr hdcSrc, int nXSrc, int nYSrc, int dwRop);
        private void button_Print_Click(object sender, EventArgs e)
        {
            CaptureScreen();
            printDocument1.PrintPage += new System.Drawing.Printing.PrintPageEventHandler(this.printDocument1_PrintPage);
            printDocument1.OriginAtMargins = true;
            pageSetupDialog1.Document = printDocument1;            //显示打印配置页面
            if (this.pageSetupDialog1.ShowDialog() == DialogResult.OK)
            {
                printPreviewDialog1.Document = printDocument1;
                //显示打印预览界面                try
                {
                    printPreviewDialog1.ShowDialog();
                }
                catch (Exception excep)
                {
                    MessageBox.Show(excep.Message, "打印出错", MessageBoxButtons.OK, MessageBoxIcon.Error);
                }
            }
        }
        private void printDocument1_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)
        {
            e.Graphics.DrawImage(memoryImage, 0, 0);
                   }       
        private void CaptureScreen()
        {
            //打印整个界面
            Graphics mygraphics = this.CreateGraphics();
            Size s = this.Size;
            memoryImage = new Bitmap(s.Width, s.Height, mygraphics);            Graphics memoryGraphics = Graphics.FromImage(memoryImage);
            IntPtr dc1 = mygraphics.GetHdc();
            IntPtr dc2 = memoryGraphics.GetHdc();
            BitBlt(dc2, 0, 0, this.ClientRectangle.Width, this.ClientRectangle.Height, dc1, 0, 0, 13369376);
            mygraphics.ReleaseHdc(dc1);
            memoryGraphics.ReleaseHdc(dc2);
        }