打印winform界面

 [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 Bitmap memoryImage;

private void buttonDaYin_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
            pageSetupDialog1.ShowDialog();
            printPreviewDialog1.Document = printDocument1;
            //显示打印预览界面
            printPreviewDialog1.ShowDialog();
        }

        private void printDocument1_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)
        {            
                        e.Graphics.DrawImage(memoryImage, 0, 0);
        }
        private void CaptureScreen()
        {
            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);
        }