1. NuGet搜索Free Spire.XLS安装,添加命名空间:using Spire.Xls;
    读取加密xlsx或xls文件:
    1. Workbook workbook = new Workbook();
    2. workbook.OpenPassword = "password";
    3. workbook.LoadFromFile("input.xlsx");
    4. Worksheet sheet = workbook.Worksheets[0];
    5. //......
    6. workbook.SaveToFile("output.xlsx", ExcelVersion.Version2013);
    1. spire.xls.dll的读取方法:
    1. using Spire.Xls;
    2. namespace ReadWordbook_XLSX
    3. {
    4. class Program
    5. {
    6. static void Main(string[] args)
    7. {
    8. Workbook workbook = new Workbook();
    9. workbook.OpenPassword = "123";//文档密码
    10. workbook.LoadFromFile("Sample.xlsx", ExcelVersion.Version2013);//加载excel文档
    11. }
    12. }
    13. }
    1. 打开文件之前加一句
    1. Biff8EncryptionKey.CurrentPassword="密码"
    读取xls文件用HSSF,xlsx文件用XSSF