using NPOI.HSSF.UserModel;
using NPOI.SS.UserModel;

 

/// <summary>
    /// DataTable导出Excel
    /// </summary>
    /// <param name="dt">datatable数据源</param>
    /// <param name="strFileName">文件名</param>
    /// <param name="strSheetName">工作簿名</param>
    public void ExportExcel(DataTable dt, string strFileName, string strSheetName)
    {
        HSSFWorkbook book = new HSSFWorkbook();
        ISheet sheet = book.CreateSheet(strSheetName);

        IRow headerrow = sheet.CreateRow(0);
        ICellStyle style = book.CreateCellStyle();
        style.Alignment = HorizontalAlignment.Center;
        style.VerticalAlignment = VerticalAlignment.Center;

        HSSFRow dataRow = (HSSFRow)sheet.CreateRow(0);
        string strColumns = "治具编号,验收项目,数据,连片类型,Gerber,光板料号,适用机种,制作厂家,厂商确认,进厂日期,应力测试日期";
        string[] strArry = strColumns.Split(',');
        for (int i = 0; i < strArry.Length; i++)
        {
            dataRow.CreateCell(i).SetCellValue(strArry[i]);
            dataRow.GetCell(i).CellStyle = style;
        }

        for (int i = 0; i < dt.Rows.Count; i++)
        {
            dataRow = (HSSFRow)sheet.CreateRow(i + 1);
            for (int j = 0; j < dt.Columns.Count; j++)
            {
                string ValueType = "";
                string Value = "";
                if (dt.Rows[i][j].ToString() != null)
                {
                    ValueType = dt.Rows[i][j].GetType().ToString();
                    Value = dt.Rows[i][j].ToString();
                }
                switch (ValueType)
                {
                    case "System.String"://字符串类型
                        dataRow.CreateCell(j).SetCellValue(Value);
                        break;
                    case "System.DateTime"://日期类型
                        System.DateTime dateV;
                        System.DateTime.TryParse(Value, out dateV);
                        dataRow.CreateCell(j).SetCellValue(dateV);
                        break;
                    case "System.Boolean"://布尔型
                        bool boolV = false;
                        bool.TryParse(Value, out boolV);
                        dataRow.CreateCell(j).SetCellValue(boolV);
                        break;
                    case "System.Int16"://整型
                    case "System.Int32":
                    case "System.Int64":
                    case "System.Byte":
                        int intV = 0;
                        int.TryParse(Value, out intV);
                        dataRow.CreateCell(j).SetCellValue(intV);
                        break;
                    case "System.Decimal"://浮点型
                    case "System.Double":
                        double doubV = 0;
                        double.TryParse(Value, out doubV);
                        dataRow.CreateCell(j).SetCellValue(doubV);
                        break;
                    case "System.DBNull"://空值处理
                        dataRow.CreateCell(j).SetCellValue("");
                        break;
                    default:
                        dataRow.CreateCell(j).SetCellValue("");
                        break;
                }
                dataRow.GetCell(j).CellStyle = style;
                //设置宽度
                sheet.SetColumnWidth(j, (Value.Length + 10) * 256);
            }
        }

        MemoryStream ms = new MemoryStream();
        book.Write(ms);
        Response.AddHeader("Content-Disposition", string.Format("attachment; filename={0}.xls", HttpUtility.UrlEncode(strFileName, System.Text.Encoding.UTF8)));
        Response.BinaryWrite(ms.ToArray());
        Response.End();
        book = null;
        ms.Close();
        ms.Dispose();
    }