DataSet,DataTable 不使用EXCEL组件直接保存为EXCEL

 B/S模式下DataSet导出保存为EXCEL直接可以Respone出来，比较简单，而C/S模式下将DataSet导出到EXCEL相对比较麻烦，要使用EXCEL要引用Microsoft.Office.Interop.Excel，经常会出现一些EXCEL进程无法关闭的问题，很让人厌恶，查看了网上一些资料，其实EXCEL也是有他自己的固定的XML格式的
。具体格式如下，首先要先定义好它的头部分，显示出来的EXCEL 才不会错误。

public  string ExcelHeader()
        {
            System.Text.StringBuilder sb = new System.Text.StringBuilder();
            sb.Append("<?xml version=\"1.0\"?>\n");
            sb.Append("<?mso-application progid=\"Excel.Sheet\"?>\n");
            sb.Append(
              "<Workbook xmlns=\"urn:schemas-microsoft-com:office:spreadsheet\" ");
            sb.Append("xmlns:o=\"urn:schemas-microsoft-com:office:office\" ");
            sb.Append("xmlns:x=\"urn:schemas-microsoft-com:office:excel\" ");
            sb.Append("xmlns:ss=\"urn:schemas-microsoft-com:office:spreadsheet\" ");
            sb.Append("xmlns:html=\"http://www.w3.org/TR/REC-html40\">\n");
            sb.Append(
              "<DocumentProperties xmlns=\"urn:schemas-microsoft-com:office:office\">");
            sb.Append("</DocumentProperties>");
            sb.Append(
              "<ExcelWorkbook xmlns=\"urn:schemas-microsoft-com:office:excel\">\n");
            sb.Append("<ProtectStructure>False</ProtectStructure>\n");
            sb.Append("<ProtectWindows>False</ProtectWindows>\n");
            sb.Append("</ExcelWorkbook>\n");
            return sb.ToString();
        }

接下来就是具体的内容了，包括DATASET,DATATABLE，等数据源

public void exportToExcel(DataSet source, string fileName)
        {
            position = 0;
            System.IO.StreamWriter excelDoc;

            excelDoc = new System.IO.StreamWriter(fileName);
            string startExcelXML = ExcelHeader();
            startExcelXML += "<Styles>\r\n " +
                "<Style ss:ID=\"Default\" ss:Name=\"Normal\">\r\n " +
                "<Alignment ss:Vertical=\"Bottom\"/>\r\n <Borders/>" +
                "\r\n <Font/>\r\n <Interior/>\r\n <NumberFormat/>" +
                "\r\n <Protection/>\r\n </Style>\r\n " +
                "<Style ss:ID=\"BoldColumn\">\r\n <Font " +
                "x:Family=\"Swiss\" ss:Bold=\"1\"/>\r\n </Style>\r\n " +
                "<Style ss:ID=\"StringLiteral\">\r\n <NumberFormat" +
                " ss:Format=\"@\"/>\r\n </Style>\r\n <Style " +
                "ss:ID=\"Decimal\">\r\n <NumberFormat " +
                "ss:Format=\"0.0000\"/>\r\n </Style>\r\n " +
                "<Style ss:ID=\"Integer\">\r\n <NumberFormat " +
                "ss:Format=\"0\"/>\r\n </Style>\r\n <Style " +
                "ss:ID=\"DateLiteral\">\r\n <NumberFormat " +
                "ss:Format=\"mm/dd/yyyy;@\"/>\r\n </Style>\r\n " +
                "</Styles>\r\n ";
            const string endExcelXML = "</Workbook>";

            int rowCount = 0;
            int sheetCount = 1;
          
            excelDoc.Write(startExcelXML);
            excelDoc.Write("<Worksheet ss:Name=\"Sheet" + sheetCount + "\">");
            excelDoc.Write("<Table>");
            excelDoc.Write("<Row>");
            for (int x = 0; x < source.Tables[0].Columns.Count; x++)
            {
                excelDoc.Write("<Cell ss:StyleID=\"BoldColumn\"><Data ss:Type=\"String\">");
                excelDoc.Write(source.Tables[0].Columns[x].ColumnName);
                excelDoc.Write("</Data></Cell>");
            }
            excelDoc.Write("</Row>");
            foreach (DataRow x in source.Tables[0].Rows)
            {
                rowCount++;
//Excel 最多只能显示64000条数据，在同一个WorkSheet里
                if (rowCount == 64000)
                {
                    rowCount = 0;
                    sheetCount++;
                    excelDoc.Write("</Table>");
                    excelDoc.Write(" </Worksheet>");
                    excelDoc.Write("<Worksheet ss:Name=\"Sheet" + sheetCount + "\">");
                    excelDoc.Write("<Table>");
                }
                excelDoc.Write("<Row>"); //ID=" + rowCount + "
                for (int y = 0; y < source.Tables[0].Columns.Count; y++)
                {
                    System.Type rowType;
                    rowType = x[y].GetType();
                    switch (rowType.ToString())
                    {
                        case "System.String":
                            string XMLstring = x[y].ToString();
                            XMLstring = XMLstring.Trim();
                            XMLstring = XMLstring.Replace("&", "&");
                            XMLstring = XMLstring.Replace(">", ">");
                            XMLstring = XMLstring.Replace("<", "<");
                            excelDoc.Write("<Cell ss:StyleID=\"StringLiteral\">" +
                                           "<Data ss:Type=\"String\">");
                            excelDoc.Write(XMLstring);
                            excelDoc.Write("</Data></Cell>");
                            break;
                        case "System.DateTime": 

                            DateTime XMLDate = (DateTime)x[y];
                            string XMLDatetoString = ""; //Excel Converted Date
                            XMLDatetoString = XMLDate.Year.ToString() +
                                 "-" +
                                 (XMLDate.Month < 10 ? "0" +
                                 XMLDate.Month.ToString() : XMLDate.Month.ToString()) +
                                 "-" +
                                 (XMLDate.Day < 10 ? "0" +
                                 XMLDate.Day.ToString() : XMLDate.Day.ToString()) +
                                 "T" +
                                 (XMLDate.Hour < 10 ? "0" +
                                 XMLDate.Hour.ToString() : XMLDate.Hour.ToString()) +
                                 ":" +
                                 (XMLDate.Minute < 10 ? "0" +
                                 XMLDate.Minute.ToString() : XMLDate.Minute.ToString()) +
                                 ":" +
                                 (XMLDate.Second < 10 ? "0" +
                                 XMLDate.Second.ToString() : XMLDate.Second.ToString()) +
                                 ".000";
                            excelDoc.Write("<Cell ss:StyleID=\"DateLiteral\">" +
                                         "<Data ss:Type=\"DateTime\">");
                            excelDoc.Write(XMLDatetoString);
                            excelDoc.Write("</Data></Cell>");
                            break;
                        case "System.Boolean":
                            excelDoc.Write("<Cell ss:StyleID=\"StringLiteral\">" +
                                        "<Data ss:Type=\"String\">");
                            excelDoc.Write(x[y].ToString());
                            excelDoc.Write("</Data></Cell>");
                            break;
                        case "System.Int16":
                        case "System.Int32":
                        case "System.Int64":
                        case "System.Byte":
                            excelDoc.Write("<Cell ss:StyleID=\"Integer\">" +
                                    "<Data ss:Type=\"Number\">");
                            excelDoc.Write(x[y].ToString());
                            excelDoc.Write("</Data></Cell>");
                            break;
                        case "System.Decimal":
                        case "System.Double":
                            excelDoc.Write("<Cell ss:StyleID=\"Decimal\">" +
                                  "<Data ss:Type=\"Number\">");
                            excelDoc.Write(x[y].ToString());
                            excelDoc.Write("</Data></Cell>");
                            break;
                        case "System.DBNull":
                            excelDoc.Write("<Cell ss:StyleID=\"StringLiteral\">" +
                                  "<Data ss:Type=\"String\">");
                            excelDoc.Write("");
                            excelDoc.Write("</Data></Cell>");
                            break;
                        default:
                            throw (new Exception(rowType.ToString() + " not handled."));
                    }
                    position = y;
                    ProgressEventArgs pe = new ProgressEventArgs(position);
                    OnProgressChange(pe);
                }
                excelDoc.Write("</Row>");
            }
            excelDoc.Write("</Table>");
            excelDoc.Write(" </Worksheet>");
            excelDoc.Write(endExcelXML);
            excelDoc.Close();
        }
}