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             #endregion

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

             // 首列
             NPOI.SS.UserModel.IRow row = sheet.CreateRow();
             row.CreateCell().SetCellValue("序号");
             row.CreateCell().SetCellValue("所在单位");
             row.CreateCell().SetCellValue("所在部门");
             row.CreateCell().SetCellValue("姓名");
             row.CreateCell().SetCellValue("职务");
             row.CreateCell().SetCellValue("性别");
             row.CreateCell().SetCellValue("民族");
             row.CreateCell().SetCellValue("出生年月");
             row.CreateCell().SetCellValue("组");
             row.CreateCell().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 = ;

             foreach (DataRow r in dt.Rows)
             {
                 NPOI.SS.UserModel.IRow dataRow = sheet.CreateRow(rowIndex);
                 string str = r["StuDentIdCard"].ToString().Substring(, );
                 str = str.Substring(, ) + "-" + str.Substring(, ) + "-" + str.Substring(, );
                 dataRow.CreateCell().SetCellValue(rowIndex.ToString());
                 dataRow.CreateCell().SetCellValue(r["StudentUnit"].ToString());
                 dataRow.CreateCell().SetCellValue(r["StudentDepartment"].ToString());
                 dataRow.CreateCell().SetCellValue(r["StudentName"].ToString());
                 dataRow.CreateCell().SetCellValue(r["StudentPosition"].ToString());
                 dataRow.CreateCell().SetCellValue(r["StudentGender"].ToString() == "" ? "男" : "女");
                 dataRow.CreateCell().SetCellValue(r["StudentNation"].ToString());
                 dataRow.CreateCell().SetCellValue(str);
                 dataRow.CreateCell().SetCellValue(r["TrainShiftNum"].ToString());
                 dataRow.CreateCell().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()[];

                         }

                         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：