将GridView导出到Excel，并在网页上显示完全相同的样式

protected void ExportToExcel_Click(object sender, EventArgs e)
{
    // 创建Excel文件
    var excelPackage = new ExcelPackage();
    var worksheet = excelPackage.Workbook.Worksheets.Add("Sheet1");

    // 导出GridView数据到Excel
    for (int i = 0; i < GridView1.Rows.Count; i++)
    {
        for (int j = 0; j < GridView1.Columns.Count; j++)
        {
            // 写入数据
            worksheet.Cells[i + 1, j + 1].Value = GridView1.Rows[i].Cells[j].Text;

            // 应用样式
            var cellStyle = worksheet.Cells[i + 1, j + 1].Style;
            cellStyle.Font.Bold = GridView1.Rows[i].Cells[j].Font.Bold;
            cellStyle.Font.Italic = GridView1.Rows[i].Cells[j].Font.Italic;
            cellStyle.Font.UnderLine = GridView1.Rows[i].Cells[j].Font.Underline;
            cellStyle.Font.Color.SetColor(GridView1.Rows[i].Cells[j].ForeColor);
            cellStyle.HorizontalAlignment = ExcelHorizontalAlignment.Center;
            cellStyle.VerticalAlignment = ExcelVerticalAlignment.Center;
        }
    }

    // 保存Excel文件到服务器
    var filePath = Server.MapPath("~/ExcelFiles/GridViewExport.xlsx");
    excelPackage.SaveAs(new FileInfo(filePath));

    // 提供下载链接
    Response.ContentType = "application/vnd.ms-excel";
    Response.AppendHeader("Content-Disposition", "attachment; filename=GridViewExport.xlsx");
    Response.TransmitFile(filePath);
    Response.End();
}