DataSet导出到Excel文件

        public static void ExportToExcel(DataSet source, string fileName)
        {
            System.IO.StreamWriter excelDoc = new System.IO.StreamWriter(fileName);
            ExportToExcel(source, excelDoc);
        }

        public static void ExportToExcel(DataTable dtSource, string fileName)
        {
            DataSet dsSource = new DataSet();
            dsSource.Tables.Add(dtSource);

            ExportToExcel(dsSource, fileName);
        }

        public static void ExportToExcel(DataTable dtSource, System.IO.StreamWriter excelDoc)
        {
            DataSet dsSource = new DataSet();
            dsSource.Tables.Add(dtSource);

            ExportToExcel(dsSource, excelDoc);
        }

        public static void ExportToExcel(DataSet source, System.IO.StreamWriter excelDoc)
        {
            const string startExcelXML = "<xml version>
<Workbook " +
                  "xmlns="urn:schemas-microsoft-com:office:spreadsheet"
" +
                  " xmlns:o="urn:schemas-microsoft-com:office:office"
 " +
                  "xmlns:x="urn:schemas-    microsoft-com:office:" +
                  "excel"
 xmlns:ss="urn:schemas-microsoft-com:" +
                  "office:spreadsheet">
 <Styles>
 " +
                  "<Style ss:ID="Default" ss:Name="Normal">
 " +
                  "<Alignment ss:Vertical="Bottom"/>
 <Borders/>" +
                  "
 <Font/>
 <Interior/>
 <NumberFormat/>" +
                  "
 <Protection/>
 </Style>
 " +
                  "<Style ss:ID="BoldColumn">
 <Font " +
                  "x:Family="Swiss" ss:Bold="1"/>
 </Style>
 " +
                  "<Style     ss:ID="StringLiteral">
 <NumberFormat" +
                  " ss:Format="@"/>
 </Style>
 <Style " +
                  "ss:ID="Decimal">
 <NumberFormat " +
                  "ss:Format="0"/>
 </Style>
 " +
                  "<Style ss:ID="Integer">
 <NumberFormat " +
                  "ss:Format="0"/>
 </Style>
 <Style " +
                  "ss:ID="DateLiteral">
 <NumberFormat " +
                  "ss:Format="mm/dd/yyyy;@"/>
 </Style>
 " +
                  "</Styles>
 ";
            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++;
                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>");
                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 = "";
                            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."));
                    }
                }
                excelDoc.Write("</Row>");
            }
            excelDoc.Write("</Table>");
            excelDoc.Write(" </Worksheet>");
            excelDoc.Write(endExcelXML);
            excelDoc.Close();
        }