Bitmap imgGroup = new Bitmap(1055, 869); 
    groupBox1.DrawToBitmap( imgGroup,groupBox1.ClientRectangle );  // 将控件保存为图片,存入imgGroup

    PrintPreviewDialog pd = new PrintPreviewDialog();
    pd.Document = new System.Drawing.Printing.PrintDocument();
    ptPreDlg.Document.DefaultPageSettings.Landscape  = true; 
    pd.Document.PrintPage += new System.Drawing.Printing.PrintPageEventHandler(Document_PrintPage);
    pd.ShowDialog(this);

void Document_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)
{
    e.Graphics.DrawImage(imgGroup , 0, 0);
}