C# 字符流打印类

usingSystem;
usingSystem.Collections.Generic;
usingSystem.Linq;
usingSystem.Text;
usingSystem.Windows.Forms;
usingSystem.Drawing;
usingSystem.Drawing.Printing;
usingSystem.IO;
usingSystem.Runtime.InteropServices;
namespacePrintService
{
    sealed classTextFilePrinter
    {
        stringsTreamPriStr;
        Encoding theEncode;
        Font theFont;
        StreamReader srToPrint;
        intcurrPage;
        public TextFilePrinter(stringsTreamPriStr)
            : this(sTreamPriStr, Encoding.GetEncoding("utf-8"), new Font("新宋体", 10))
        {
        }
        public TextFilePrinter(stringsTreamPriStr, Encoding theEncode, Font theFont)
        {
            this.sTreamPriStr =sTreamPriStr;
            this.theEncode =theEncode;
            this.theFont =theFont;
        }
        public voidPrint()
        {
            srToPrint = new StreamReader(newMemoryStream(Encoding.UTF8.GetBytes(sTreamPriStr)));
            PrintDialog dlg = newPrintDialog();
            dlg.Document =GetPrintDocument();
            dlg.AllowSomePages = true;
            dlg.AllowPrintToFile = false;
            if (dlg.ShowDialog() ==DialogResult.OK) dlg.Document.Print();
        }
        /// <summary>
        ///不需要打印预览直接打印
        /// </summary>
        public voidPrint2()
        {
            srToPrint = new StreamReader(newMemoryStream(Encoding.UTF8.GetBytes(sTreamPriStr)));
            PrintDialog dlg = newPrintDialog();
            dlg.Document =GetPrintDocument();
            dlg.AllowSomePages = true;
            dlg.AllowPrintToFile = false;
            dlg.Document.Print();
        }
        public voidView()
        {
            srToPrint = new StreamReader(newMemoryStream(Encoding.UTF8.GetBytes(sTreamPriStr)));
            PrintPreviewDialog dlg = newPrintPreviewDialog();
            dlg.Document =GetPrintDocument();
            dlg.ShowDialog();
        }
        PrintDocument GetPrintDocument()
        {
            currPage = 1;
            PrintDocument doc = newPrintDocument();
            doc.DocumentName = "打印";
            doc.PrintPage += newPrintPageEventHandler(PrintPageEvent);
            returndoc;
        }
        void PrintPageEvent(objectsender, PrintPageEventArgs ev)
        {
            string line = null;
            float linesPerPage = ev.MarginBounds.Height /theFont.GetHeight(ev.Graphics);
            bool isSomePages = ev.PageSettings.PrinterSettings.PrintRange ==PrintRange.SomePages;
            if(isSomePages)
            {
                while (currPage <ev.PageSettings.PrinterSettings.FromPage)
                {
                    for (int count = 0; count < linesPerPage; count++)
                    {
                        line =srToPrint.ReadLine();
                        if (line == null) break;
                    }
                    if (line == null) return;
                    currPage++;
                }
                if (currPage > ev.PageSettings.PrinterSettings.ToPage) return;
            }
            for (int count = 0; count < linesPerPage; count++)
            {
                line =srToPrint.ReadLine();
                if (line == null) break;
                //ev.Graphics.DrawString(line, theFont, Brushes.Black, ev.MarginBounds.Left,
                //ev.MarginBounds.Top + (count * theFont.GetHeight(ev.Graphics)), new StringFormat());

                ev.Graphics.DrawString(line, theFont, Brushes.Black, 2,
                  count * theFont.GetHeight(ev.Graphics) - 1, newStringFormat());
            }
            currPage++;
            if (isSomePages && currPage > ev.PageSettings.PrinterSettings.ToPage) return;
            if (line != null) ev.HasMorePages = true;
        }
    }
    public static classPrinterHel
    {
        //GetDefaultPrinter用到的API函数说明 
        [DllImport("winspool.drv", CharSet = CharSet.Auto, SetLastError = true)]
        internal static extern bool GetDefaultPrinter(StringBuilder pszBuffer, ref intsize);
        //SetDefaultPrinter用到的API函数声明 
        [DllImport("winspool.drv", CharSet = CharSet.Auto, SetLastError = true)]
        internal static extern bool SetDefaultPrinter(stringName);
        #region 获取本地打印机列表
        /// <summary> 
        ///获取本地打印机列表 
        /// </summary> 
        /// <returns>打印机列表</returns> 
        public static List<string>GetPrinterList()
        {
            List<string> printRet =Cprinter.GetLocalPrinter();
            returnprintRet;
        }
        #endregion 获取本地打印机列表
        #region 获取本机的默认打印机名称
        /// <summary> 
        ///获取本机的默认打印机名称 
        /// </summary> 
        /// <returns>默认打印机名称</returns> 
        public static stringGetDeaultPrinterName()
        {
            StringBuilder dp = new StringBuilder(256);
            int size =dp.Capacity;
            if (GetDefaultPrinter(dp, refsize))
            {
                returndp.ToString();
            }
            else
            {
                return string.Empty;
            }
        }
        #endregion 获取本机的默认打印机名称
        #region 设置默认打印机
        /// <summary> 
        ///设置默认打印机 
        /// </summary> 
        /// <param name="PrinterName">可用的打印机名称</param> 
        public static void SetPrinterToDefault(stringPrinterName)
        {
            SetDefaultPrinter(PrinterName);
        }
        #endregion 设置默认打印机
        #region 判断打印机是否在系统可用的打印机列表中
        ///// <summary> 
        ///// 判断打印机是否在系统可用的打印机列表中 
        ///// </summary> 
        ///// <param name="PrinterName">打印机名称</param> 
        ///// <returns>是：在；否：不在</returns> 
        public static bool PrinterInList(stringPrinterName)
        {
            bool bolRet = false;
            List<string> alPrinters =GetPrinterList();
            for (int i = 0; i < alPrinters.Count; i++)
            {
                if (PrinterName ==alPrinters[i].ToString())
                {
                    bolRet = true;
                    break;
                }
            }
            alPrinters.Clear();
            alPrinters = null;
            returnbolRet;
        }
        #endregion 判断打印机是否在系统可用的打印机列表中
    }
}