导入Excel表格的插件叫做EPPlus

只需要在NuGet引用，然后如数以下代码:

using Microsoft.AspNetCore.Http;
using OfficeOpenXml;
using System.Data;
using System.IO;
using System.Linq;

namespace Import
{
    public class EPPlusHelper
    {
        /// <summary>
        /// Exlce转datatable
        /// </summary>
        /// <param name="file"></param>
        /// <returns></returns>
        public static DataTable ExcelTransformationDataTable(IFormFile file)
        {
            using (var memoryStream = new MemoryStream())
            {
                DataTable dt = null;
                file.CopyToAsync(memoryStream).ConfigureAwait(false);
                using (var package = new ExcelPackage(memoryStream))
                {
                    ExcelWorkbook workbook = package.Workbook;
                    if (workbook != null)
                    {
                        if (workbook.Worksheets.Count > 0)
                        {
                            ExcelWorksheet worksheet = workbook.Worksheets.First();
                            dt = ExlceToTable(worksheet);
                        }
                    }
                }
                return dt;
            }
        }
        private static DataTable? ExlceToTable(ExcelWorksheet worksheet)
        {
            //获取表格有多少行
            int rows = worksheet.Dimension.End.Row;
            //获取表格有多少列
            int cols = worksheet.Dimension.End.Column;
            //创建一个datatable
            DataTable data = new DataTable(worksheet.Name);
            //创建一行
            DataRow row = null;
            //循环行数
            for (int i = 1; i <= rows; i++)
            {
                if (i > 1)
                {
                    row = data.Rows.Add();
                }
                for (int j = 1; j <= cols; j++)
                {
                    //把第一行设置为DataTable的标题
                    if (i == 1)
                    {
                        data.Columns.Add(worksheet.Cells[i, j].Value?.ToString());
                    }
                    else
                    {
                        row[j - 1] = worksheet.Cells[i, j].Value?.ToString();
                    }
                }
            }
            return data;
        }
    }
}

 最后需要在appsettings.json中输入以下配置信息：

{
  "EPPlus": {
    "ExcelPackage": {
      "LicenseContext": "Commercial" //The license context used
    }
  },
  
  "AllowedHosts": "*"
}