参考网址 :https://www.cnblogs.com/landeanfen/p/5888973.html
1、下载spire.xls.dll文件,添加引用
https://www.e-iceblue.com/Download/download-excel-for-net-now.html
2、
using Spire.Xls;
//创建Workbook对象
Workbook wb = new Workbook();
//加载Excel文档
wb.LoadFromFile(Excel文件路径);
//获取第一个工作表
Worksheet sheet = wb.Worksheets[0];
//获取指定单元格的值
valueA1 = sheet.Range["A1"].Value2.ToString();
valueB1 = sheet.Range["B1"].Value2.ToString();