namespace XSGLSRV900 //服务端接口实现{    public class XSGLService : IXSGLService    {//这些变量只能是静态的，如果是非静态的，在客户端每一次调用服务端都认为是新建一个服务对象，这些值将不再能读取到。关于WCF服务端的三种模式可参考http://www.cnblogs.com/tyb1222/archive/2012/10/12/2721252.html
//这样静态的是有缺陷的，对所有客户端建立的服务端都用这些静态变量，一旦某一个用户使其值改变即便前一个用户还没读取完List值也是不管的，没找到更好的解决办法       private static List<StringBuilder> LStringBuilder = new List<StringBuilder>();        private static int Count = 0;        private static int Cur_INX = 0;        public int BFBHDDSQLQuery_txt(string sSQL,ref List<string>Datas ,ref List<String> OutERROR)        {            int iERROR = 0;            DataSet ds = null;            List<string> exERROR = new List<string>();           //这里要使用StringBuilder，不能用string类型的，以为没对string进行一次操作都会在内存中新建一个对象，如果频繁操作很费时间。           //这里在new时需要用带餐的构造函数，否则默认的长度不够            StringBuilder ss = new StringBuilder(100, Int32.MaxValue);            LStringBuilder = new List<StringBuilder>();            Datas = new List<string>();            int iCount = 0;            Count = 0;            Cur_INX = 0;            DbConnection conn = bf.srv.framework.bflib.PubData.GetDbConnection(BHServerPlatform.iBFBHDD);            try            {                CyQuery query = new CyQuery(conn);                try                {                            //这里加"\t" tab键实现txt对齐，再从txt转换成excel时也能保证对其                             ss.Append("交易时间\t");//交易时间                    ss.Append("结账日期\t");//结账日期                    ss.Append("交易流水号\t");//交易流水号                    ss.Append("部门代码\t");//部门代码                    ss.Append("商标\t");//商标                    ss.Append("商品代码\t");//商品代码                    ss.Append("收款方式\t");//收款方式                    ss.Append("收款金额\t");//收款金额                    ss.Append("收款台号\t");//收款台号                    ss.Append("\r\n");                    query.SQL.Text = sSQL;                    query.SQL.Text = sSQL;                    query.Open();                                                         while (!query.Eof) //当Query是IsEmpty时，不能取值                    {                        ss.Append( query.Fields[0].AsDateTime.ToString()+"\t");//交易时间                        ss.Append(query.Fields[1].AsDateTime.ToShortDateString() + "\t");//结账日期                        ss.Append(query.Fields[2].AsInteger.ToString() + "\t");//交易流水号                        ss.Append(query.Fields[3].AsString + "\t");//部门代码                        ss.Append(query.Fields[4].AsInteger.ToString() + "\t");//商标                        ss.Append(query.Fields[5].AsString.ToString() + "\t");//商品代码                        ss.Append(query.Fields[6].AsInteger.ToString() + "\t");//收款方式                        ss.Append(query.Fields[7].AsDecimal.ToString() + "\t");//收款金额                        ss.Append(query.Fields[8].AsString + "\t");//收款台号                                                ss.Append( "\r\n");                        iCount += 1;//这里要把字符串分开成若干个，否则在服务端往客户端传输时会因为数据量太大而报错，连接意外关闭，分成若干个，在客户端一段段读取不会有这个问题就                        if (iCount %100000==0)                        {                            Count++;                            LStringBuilder.Add(ss); //Datas.Add(ss.ToString());                            //ss.Clear();                            ss = new StringBuilder(100, Int32.MaxValue);                        }                                               query.Next();                    }                    if (iCount % 100000 != 0)                    {                        Count++;                        LStringBuilder.Add(ss);                        //ss.Clear();                        ss = new StringBuilder(100, Int32.MaxValue);                    }                    if (iCount > 0)                    {                        //chars = new char[ss.Length];                        //ss.CopyTo(0, chars, 0, ss.Length);                    }                    query.Close();                }                catch (Exception e)                {                    iERROR = 1;                    BHServerPlatform.WriteErrorLog(e.GetType().ToString() + "," + e.StackTrace + ":" + query.SqlText);                    exERROR.Add(e.Message);                }            }            catch (Exception e)            {                iERROR = 1;                exERROR.Add(e.Message);            }            finally            {                conn.Close();            }            OutERROR = exERROR;            return iERROR;        }        public String GetStringBuilder()        {            if (Cur_INX < Count)            {                Cur_INX++;                return LStringBuilder[Cur_INX-1].ToString();            }            else                return "";        }        public bool GetString()        {            if (Cur_INX < Count)            {                return true;            }            else                return false;        }     }

}

        private void btn_DC_Click(object sender, RoutedEventArgs e)//客户端实现导出txt        {            Microsoft.Win32.SaveFileDialog MysaveFileDialog = new Microsoft.Win32.SaveFileDialog();            string MyExpName = "txt";            string fileName = txt_DC.Text.Trim();            string strPath = Environment.CurrentDirectory;            MysaveFileDialog.DefaultExt = MyExpName;//默认扩展名            MysaveFileDialog.AddExtension = true;//是否自动添加扩展名            MysaveFileDialog.Filter = "*." + MyExpName + "|." + MyExpName;            MysaveFileDialog.OverwritePrompt = true;//文件已存在是否提示覆盖            MysaveFileDialog.FileName = fileName;            //dialogOpenFile.FileName = "文件名";//默认文件名            MysaveFileDialog.CheckPathExists = true;//提示输入的文件名无效            MysaveFileDialog.Title = "对话框标题";            //显示对话框            bool? b = MysaveFileDialog.ShowDialog();            if (b == true)//点击保存            {                fileName = MysaveFileDialog.FileName;                txt_DC.Text = fileName;                //恢复系统路径-涉及不到的可以去掉                Environment.CurrentDirectory = strPath;            }            else            {                //恢复系统路径-涉及不到的可以去掉                Environment.CurrentDirectory = strPath;                return;            }                        List<string> Datas = new List<string>();            try            {                if (true)//(File.Exists(fileName))                {                    string sSQL = MakeSQL();                    List<string> ERR = new List<string>();                    int iRe = MyXSGLService.BFBHDDSQLQuery_txt(sSQL, ref Datas, ref ERR);                    if (iRe != 0)                    {                        PubData.bflibShowError(Application.Current.MainWindow, ERR);                        return;                    }                    else                    {                                                Stream stream = MysaveFileDialog.OpenFile();                        while (MyXSGLService.GetString())                        {                            Byte[] fileContent = System.Text.Encoding.GetEncoding("gb2312").GetBytes(MyXSGLService.GetStringBuilder());                            stream.Write(fileContent, 0, fileContent.Length);                        }                        stream.Close();                                                MessageBox.Show("导出完成！");                    }                }            }            catch (Exception ex)            {                MessageBox.Show(ex.Message);            }                    }