使用NPOI完成导出Excel文件

参考网址：http://blog.csdn.net/tiemufeng1122/article/details/6732588

能够实现  点击按钮弹出下载框    的功能，如图：

HTML代码：

 <button type="button" class="bk-margin-5 btn btn-success" onclick="printExcel()">Excel导出</button>

<script type="text/javascript">
 function printExcel() {
            post("PrintExcel", null); //如果调用时有参数，则post("PrintExcel",{id:id});
        }
        function post(URL, PARAMS) {
            var temp = document.createElement("form");
            temp.action = URL;
            temp.method = "post";
            temp.style.display = "none";
            for (var x in PARAMS) {
                var opt = document.createElement("textarea");
                opt.name = x;
                opt.value = PARAMS[x];  
                temp.appendChild(opt);
            }
            document.body.appendChild(temp);
            temp.submit();
            return temp;
        }
</script>

后台代码：

 [HttpPost]//只接受post请求
        public void PrintExcel()
        {
            //接收参数 int id=Int32.Parse(Requert.Form["id"]);
            string trainShift = Session["trainshiftNum"].ToString(); 
            #region 转换成DataSet
            var query = from s in db.Students
                        where s.IsDelete == false && s.TrainShiftNum == trainShift
                        select new Stu
                        {
                            StudentDepartment = s.StudentDepartment,
                            StudentGender = s.StudentGender,
                            StuDentIdCard = s.StuDentIdCard,
                            StudentName = s.StudentName,
                            StudentNation = s.StudentNation,
                            StudentPosition = s.StudentPosition,
                            StudentUnit = s.StudentUnit,
                            TrainShiftNum = s.TrainShiftNum,
                            Remark = s.Remark
                        };
            DataTable dt = query.ToDataTable(rec => new object[] { query });//调用转换DataTable方法 22             #endregion

            HSSFWorkbook book = new HSSFWorkbook();
            MemoryStream ms = new MemoryStream();
            ISheet sheet = book.CreateSheet("sheet1");

            // 首列
            NPOI.SS.UserModel.IRow row = sheet.CreateRow(0);
            row.CreateCell(0).SetCellValue("序号");
            row.CreateCell(1).SetCellValue("所在单位");
            row.CreateCell(2).SetCellValue("所在部门");
            row.CreateCell(3).SetCellValue("姓名");
            row.CreateCell(4).SetCellValue("职务");
            row.CreateCell(5).SetCellValue("性别");
            row.CreateCell(6).SetCellValue("民族");
            row.CreateCell(7).SetCellValue("出生年月");
            row.CreateCell(8).SetCellValue("组");
            row.CreateCell(9).SetCellValue("备注");
            #region
            //// 第一列
            //NPOI.SS.UserModel.IRow row1 = sheet.CreateRow(1);
            //row1.CreateCell(0).SetCellValue("所在单位");

            //// 第二列
            //NPOI.SS.UserModel.IRow row2 = sheet.CreateRow(2);
            //row2.CreateCell(0).SetCellValue("所在部门");

            //// 第三列
            //NPOI.SS.UserModel.IRow row3 = sheet.CreateRow(3);
            //row3.CreateCell(0).SetCellValue("姓名");

            //// 第四列
            //NPOI.SS.UserModel.IRow row4 = sheet.CreateRow(4);
            //row4.CreateCell(0).SetCellValue("职务");

            //// 第五列
            //NPOI.SS.UserModel.IRow row5 = sheet.CreateRow(5);
            //row5.CreateCell(0).SetCellValue("性别");

            //// 第六列
            //NPOI.SS.UserModel.IRow row6 = sheet.CreateRow(6);
            //row6.CreateCell(0).SetCellValue("民族");

            //// 第七列
            //NPOI.SS.UserModel.IRow row7 = sheet.CreateRow(7);
            //row7.CreateCell(0).SetCellValue("出生年月");

            //// 第八列
            //NPOI.SS.UserModel.IRow row8 = sheet.CreateRow(8);
            //row8.CreateCell(0).SetCellValue("组");

            //// 第九列
            //NPOI.SS.UserModel.IRow row9 = sheet.CreateRow(9);
            //row9.CreateCell(0).SetCellValue("备注");
            #endregion
            int rowIndex = 1;

            foreach (DataRow r in dt.Rows)
            {
                NPOI.SS.UserModel.IRow dataRow = sheet.CreateRow(rowIndex);
                string str = r["StuDentIdCard"].ToString().Substring(6, 8);
                str = str.Substring(0, 4) + "-" + str.Substring(4, 2) + "-" + str.Substring(6, 2);
                dataRow.CreateCell(0).SetCellValue(rowIndex.ToString());
                dataRow.CreateCell(1).SetCellValue(r["StudentUnit"].ToString());
                dataRow.CreateCell(2).SetCellValue(r["StudentDepartment"].ToString());
                dataRow.CreateCell(3).SetCellValue(r["StudentName"].ToString());
                dataRow.CreateCell(4).SetCellValue(r["StudentPosition"].ToString());
                dataRow.CreateCell(5).SetCellValue(r["StudentGender"].ToString() == "1" ? "男" : "女");
                dataRow.CreateCell(6).SetCellValue(r["StudentNation"].ToString());
                dataRow.CreateCell(7).SetCellValue(str);
                dataRow.CreateCell(8).SetCellValue(r["TrainShiftNum"].ToString());
                dataRow.CreateCell(9).SetCellValue(r["Remark"].ToString());
                rowIndex++;
            }

            // 写入到客户端  
            book.Write(ms);
            //Response.ClearContent();
            //Response.Clear();
            //Response.Buffer = true;
            // 添加头信息，为"文件下载/另存为"对话框指定默认文件名   
            Response.AddHeader("Content-Disposition", string.Format("attachment; filename={0}.xls", System.DateTime.Now.ToString("yyyymmddhhmmss")));
            Response.Charset = "UTF-8";
            Response.ContentEncoding = System.Text.Encoding.GetEncoding("UTF-8");
            // 指定返回的是一个不能被客户端读取的流，必须被下载   
            Response.ContentType = "application/ms-excel";
            // 把文件流发送到客户端 
            Response.BinaryWrite(ms.ToArray());
            book = null;
            ms.Close();
            ms.Dispose();
        }

转换DataTable的代码（在网上查到的完美转换法，注意的是怎么调用）：

 public static class ListToDataTable  //可以直接使用
    {
        public static DataTable ToDataTable<T>(this IEnumerable<T> varlist, CreateRowDelegate<T> fn)
        {

            DataTable dtReturn = new DataTable();

            // column names

            PropertyInfo[] oProps = null;

            // Could add a check to verify that there is an element 0

            foreach (T rec in varlist)
            {

                // Use reflection to get property names, to create table, Only first time, others will follow

                if (oProps == null)
                {

                    oProps = ((Type)rec.GetType()).GetProperties();

                    foreach (PropertyInfo pi in oProps)
                    {

                        Type colType = pi.PropertyType; if ((colType.IsGenericType) && (colType.GetGenericTypeDefinition() == typeof(Nullable<>)))
                        {

                            colType = colType.GetGenericArguments()[0];

                        }

                        dtReturn.Columns.Add(new DataColumn(pi.Name, colType));

                    }

                }

                DataRow dr = dtReturn.NewRow(); foreach (PropertyInfo pi in oProps)
                {

                    dr[pi.Name] = pi.GetValue(rec, null) == null ? DBNull.Value : pi.GetValue(rec, null);

                }

                dtReturn.Rows.Add(dr);

            }

            return (dtReturn);

        }

        public delegate object[] CreateRowDelegate<T>(T t);

    }

还有就是类的写法：

  /// <summary>
    /// 打印学员名单
    /// </summary>
    public class Stu
    {
        private string studentUnit;

        public string StudentUnit
        {
            get { return studentUnit; }
            set { studentUnit = value; }
        }
        private string studentDepartment;

        public string StudentDepartment
        {
            get { return studentDepartment; }
            set { studentDepartment = value; }
        }
        private string studentName;

        public string StudentName
        {
            get { return studentName; }
            set { studentName = value; }
        }
        private string studentPosition;

        public string StudentPosition
        {
            get { return studentPosition; }
            set { studentPosition = value; }
        }
        private int studentGender;

        public int StudentGender
        {
            get { return studentGender; }
            set { studentGender = value; }
        }
        private string studentNation;

        public string StudentNation
        {
            get { return studentNation; }
            set { studentNation = value; }
        }
        private string stuDentIdCard;

        public string StuDentIdCard
        {
            get { return stuDentIdCard; }
            set { stuDentIdCard = value; }
        }
        private string trainShiftNum;

        public string TrainShiftNum
        {
            get { return trainShiftNum; }
            set { trainShiftNum = value; }
        }
        private string remark;

        public string Remark
        {
            get { return remark; }
            set { remark = value; }
        }
    }

结果如图：