Net Core 使用 EPPlus 下載Excel

環境：.Net Core 3.1

引用：EPPlus  5.1.2

類庫：

using OfficeOpenXml;
using OfficeOpenXml.Style;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Linq;
namespace Helper
{
    /// <summary>
    /// Excel導出幫助類
    /// </summary>
    public class ExcelExportHelper
    {
        /// <summary>
        /// List轉DataTable
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="data"></param>
        /// <returns></returns>
        public static DataTable ListToDataTable<T>(List<T> data)
        {
            PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(typeof(T));
            DataTable dataTable = new DataTable();
            for (int i = 0; i < properties.Count; i++)
            {
                PropertyDescriptor property = properties[i];
                dataTable.Columns.Add(property.Name, Nullable.GetUnderlyingType(property.PropertyType) ?? property.PropertyType);
            }
            object[] values = new object[properties.Count];
            foreach (T item in data)
            {
                for (int i = 0; i < values.Length; i++)
                {
                    values[i] = properties[i].GetValue(item);
                }
                dataTable.Rows.Add(values);
            }
            return dataTable;
        }

        /// <summary>
        /// 導出Excel
        /// </summary>
        /// <param name="dataTable">數據源</param>
        /// <param name="heading">工作簿Worksheet</param>
        /// <param name="showSrNo">是否顯示行編號</param>
        /// <param name="columnsToTake">要導出的列</param>
        /// <returns></returns>
        public static byte[] ExportExcel(DataTable dataTable, string heading = "", bool showSrNo = false, params string[] columnsToTake)
        {
            byte[] result;

            using (var package = new ExcelPackage())
            {
                var workSheet = package.Workbook.Worksheets.Add($"Sheet1");

                int startRowFrom = string.IsNullOrEmpty(heading) ? 1 : 3;  //開始的行
                //是否顯示行編號
                if (showSrNo)
                {
                    DataColumn dataColumn = dataTable.Columns.Add("#", typeof(int));
                    dataColumn.SetOrdinal(0);
                    int index = 1;
                    foreach (DataRow item in dataTable.Rows)
                    {
                        item[0] = index;
                        index++;
                    }
                }
                //將內容添加到Excel文件中
                workSheet.Cells["A" + startRowFrom].LoadFromDataTable(dataTable, true);
                // 小內容單元格的自動調整寬度
                int columnIndex = 1;
                foreach (DataColumn item in dataTable.Columns)
                {
                    ExcelRange columnCells = workSheet.Cells[workSheet.Dimension.Start.Row, columnIndex, workSheet.Dimension.End.Row, columnIndex];
                    int maxLength = columnCells.Max(cell => cell.Value.ToString().Count());
                    if (maxLength < 150)
                    {
                        workSheet.Column(columnIndex).AutoFit();
                    }
                    columnIndex++;
                }
                // 格式標題-粗體，黃底黑底
                using (ExcelRange r = workSheet.Cells[startRowFrom, 1, startRowFrom, dataTable.Columns.Count])
                {
                    r.Style.Font.Color.SetColor(System.Drawing.Color.White);
                    r.Style.Font.Bold = true;
                    r.Style.Fill.PatternType = ExcelFillStyle.Solid;
                    r.Style.Fill.BackgroundColor.SetColor(System.Drawing.ColorTranslator.FromHtml("#1fb5ad"));
                }
                // 設置單元格格式-添加邊框
                using (ExcelRange r = workSheet.Cells[startRowFrom + 1, 1, startRowFrom + dataTable.Rows.Count, dataTable.Columns.Count])
                {
                    r.Style.Border.Top.Style = ExcelBorderStyle.Thin;
                    r.Style.Border.Bottom.Style = ExcelBorderStyle.Thin;
                    r.Style.Border.Left.Style = ExcelBorderStyle.Thin;
                    r.Style.Border.Right.Style = ExcelBorderStyle.Thin;
                    r.Style.Border.Top.Color.SetColor(System.Drawing.Color.Black);
                    r.Style.Border.Bottom.Color.SetColor(System.Drawing.Color.Black);
                    r.Style.Border.Left.Color.SetColor(System.Drawing.Color.Black);
                    r.Style.Border.Right.Color.SetColor(System.Drawing.Color.Black);
                }
                //已刪除忽略的列
                for (int i = dataTable.Columns.Count - 1; i >= 0; i--)
                {
                    if (i == 0 && showSrNo)
                    {
                        continue;
                    }
                    if (!columnsToTake.Contains(dataTable.Columns[i].ColumnName))
                    {
                        workSheet.DeleteColumn(i + 1);
                    }
                }
                if (!string.IsNullOrEmpty(heading))
                {
                    workSheet.Cells["A1"].Value = heading;
                    workSheet.Cells["A1"].Style.Font.Size = 20;
                    workSheet.InsertColumn(1, 1);
                    workSheet.InsertRow(1, 1);
                    workSheet.Column(1).Width = 5;
                }
                result = package.GetAsByteArray();
            }
            return result;
        }
        /// <summary>
        /// 導出Excel
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="data">導出數據</param>
        /// <param name="heading">工作簿Worksheet</param>
        /// <param name="columnsToTake">列頭</param>
        /// <returns></returns>
        public static byte[] ExportExcel<T>(List<T> data, string heading = "", params string[] columnsToTake)
        {
            return ExportExcel(ListToDataTable(data), heading, false, columnsToTake);
        }
    }
}

類方法調用

        /// <summary>
        /// 導出Excel
        /// </summary>
        /// <returns></returns>
        public byte[] ExportExcel()
        {
            var stuList = new List<Student>()
            {
                new Student { Name = "張三", Sex = "女" },
                new Student { Name = "李四", Sex = "男" }
            };
            //列名稱與字段命名一致
            string[] columns = { "Name", "Sex" };
            byte[] filecontent = ExcelExportHelper.ExportExcel(stuList, "", columns);
            return filecontent;
        }

        public class Student
        {
            public string Name { get; set; }
            public string Sex { get; set; }
        }

控制器調用：

        /// <summary>
        /// 導出Excel
        /// </summary>
        /// <returns></returns>
        [HttpGet]
        public IActionResult ExportExcel()
        {
            var result = _stuRepository.ExportExcel();
            return File(result, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet","Student.xlsx");
        }

appsettings.json文件配置

  "EPPlus": {
    "ExcelPackage": {
      "LicenseContext": "NonCommercial" //The license context used
    }
  }

參考文檔：https://www.cnblogs.com/zhang1f/p/11093679.html