底层类：

#region DataTable 导出到 Excel

        /// <summary>

        /// DataTable 导出到 Excel

        /// </summary>

        /// <param name="dt">数据表</param>

        /// <param name="captions">要导出的列标题</param>

        /// <param name="fieldNames">要导出的列名</param>

        /// <param name="sheetName">工作簿名称</param>

        /// <param name="isOpen">导出完成是否打开Excel,如果=false会杀死当前Excel进程</param>

        /// <returns>错误信息，如果为空，说明用户取消导入</returns>

        public static string DtToExcel(DataTable dt, string[] captions, string[] fieldNames, string sheetName, bool isOpen)

        {

            //返回的信息

            string str = "";

            //保存对话框

            SaveFileDialog sfd = new SaveFileDialog();

            sfd.Filter = "(*.xls,*.xlsx)|*.xls;*.xlsx";

            //保存的文件名称

            string fileName = "";

            if (sfd.ShowDialog() != DialogResult.OK)

            {

                return "";

            }

            if (dt == null)

            {

                str = "表不能为空";

                return str;

            }

            if (captions.Length != fieldNames.Length)

            {

                str = "列名数目和列标题数目不匹配";

                return str;

            }

            foreach (string aa in fieldNames)

            {

                if (!dt.Columns.Contains(aa))

                {

                    str = "表中不存在列名为 " + aa + " 的列";

                    return str;

                }

            }

            //如果不是全部列都要导出，改变一下样式

            DataView dv = new DataView(dt);

            dt = dv.ToTable(false, fieldNames);

            //导出路径

            fileName = sfd.FileName;

            //定义Excel程序

            Microsoft.Office.Interop.Excel.Application excel = new Microsoft.Office.Interop.Excel.Application();

            //判断是否安装Excel

            if (excel == null)

            {

                str = "无法创建Excel对象,可能您的计算机未安装Excel!";

                return str;

            }

            //是否显示导出过程 ，建议关闭，否则在导出过程中鼠标点击Excel文件时会出错

            excel.Visible = false;

            //定义一个Excel文件

            Microsoft.Office.Interop.Excel.Workbook wBook = excel.Workbooks.Add(System.Reflection.Missing.Value);

            //定义工作表

            Microsoft.Office.Interop.Excel.Worksheet wSheet = (Microsoft.Office.Interop.Excel.Worksheet)wBook.Worksheets[1];

            Microsoft.Office.Interop.Excel.Range range;

            //获取行数、列数

            int rowCount = dt.Rows.Count;

            int colCount = captions.Length;

            //设置表格名称

            if (sheetName != null && sheetName.Length > 0)

            {

                wSheet.Name = sheetName;

            }

            else

            {

                wSheet.Name = dt.TableName;

            }

            if (rowCount < 1)

            {

                str = "没有记录可以导出";

                return str;

            }

            try

            {

                //写标题,标题居中

                for (int j = 1; j < captions.Length + 1; j++)

                {

                    excel.Cells[1, j] = captions[j - 1];

                }

                //设置对齐方式

                wSheet.Cells.HorizontalAlignment = Microsoft.Office.Interop.Excel.XlHAlign.xlHAlignCenter;

                //设置第一行高度，即标题栏

                ((Microsoft.Office.Interop.Excel.Range)wSheet.Rows["1:1", System.Type.Missing]).RowHeight = 20;

                //设置数据行行高度

                ((Microsoft.Office.Interop.Excel.Range)wSheet.Rows["2:" + dt.Rows.Count + 1, System.Type.Missing]).RowHeight = 16;

                //设置字体大小（10号字体）

                wSheet.Range[wSheet.Cells[1, 1], wSheet.Cells[dt.Rows.Count + 1, dt.Columns.Count]].Font.Size = 10;

                //设置单元格边框

                Microsoft.Office.Interop.Excel.Range range1 = wSheet.Range[wSheet.Cells[1, 1], wSheet.Cells[dt.Rows.Count + 1, dt.Columns.Count]];

                //往Excel写数据

                for (int m = 0; m < rowCount; m++)

                {

                    for (int n = 0; n < colCount; n++)

                    {

                        excel.Cells[m + 2, n + 1] = (object)dt.Rows[m][n] is DBNull ? "" : dt.Rows[m][n].ToString();

                    }

                }

                //保存工作表

                wSheet.SaveAs(fileName, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);

                wBook.Close(Type.Missing, Type.Missing, Type.Missing);

                ////设置EXLCE最大化

                //excel.WindowState = XlWindowState.xlMaximized;

                //提示信息

                str = "导出成功！ 共导出 " + rowCount + " 条数据";

                return str;

            }

            catch (Exception ex)

            {

                str = "导出异常，请重试";

                return str;

            }

            finally

            {

                if (isOpen)

                {

                    //前台显示给用户

                    excel.Visible = true;

                    wSheet = null;

                    excel = null;

                }

                else

                {

                    excel.Visible = false;

                    excel.Quit();

                    // excel = null;

                    //杀死Excel 进程

                    KillProcess(excel);

                }

                GC.Collect();

            }

        }

        #endregion

调用（举例）：

 string str=Functionjsj.DtToExcel(dt, new string[] { "学号", "姓名", "年龄" },

               new string[] { "Stu_Number", "Stu_Name", "Stu_Age" }, "学生信息",false);

           if (str.Length > 0) {

               MessageBox.Show(str, System.Windows.Forms.Application.ProductName);

               return;

           }