导出excel的asp.net代码

要在 ASP.NET 中导出 Excel，您可以使用如下代码：

using System;
using System.Data;
using System.IO;
using System.Web.UI;
using Microsoft.Office.Interop.Excel;

namespace ExportExcel
{
    public partial class Export : Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            DataTable dt = new DataTable();
            dt.Columns.AddRange(new DataColumn[3] { new DataColumn("Id", typeof(int)),
                                            new DataColumn("Name", typeof(string)),
                                            new DataColumn("Country",typeof(string)) });
            dt.Rows.Add(1, "John Hammond", "United States");
            dt.Rows.Add(2, "Mudassar Khan", "India");
            dt.Rows.Add(3, "Suzanne Mathews", "France");
            dt.Rows.Add(4, "Robert Schidner", "Russia");
            
            Application excel = new Application();
            Workbook workbook = excel.Workbooks.Add(Type.Missing);
            Worksheet sheet = workbook.ActiveSheet;
            sheet.Name = "ExportedFromDatatable";

            for (int i = 1; i < dt.Columns.Count + 1; i++)
            {
                sheet.Cells[1, i] = dt.Columns[i - 1].ColumnName;
            }

            for (int i = 0; i < dt.Rows.Count; i++)
            {
                for (int j = 0; j < dt.Columns.Count; j++)
                {
                    sheet.Cells[i + 2, j + 1] = dt.Rows[i][j];
                }
            }
            workbook.SaveAs(Response.OutputStream);
            Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
            Response.AddHeader("content-disposition", "attachment; filename=ExportedFile.xlsx");
            Response.Flush();
            Response.End();
        }
    }
}

请注意，上面的代码使用了 Microsoft.Office.Interop.Excel 库，因此您需要先安装该库。

这段代码会创建一个包含三列的 DataTable，分别为 Id、Name 和 Country，然后通过 Microsoft.Office.Interop.Excel 库创建 Excel 工作簿并将数据写入该工作簿。最后，通过 HTTP 响应将工作簿以 .xlsx 格式导出到客户端。