how to import excel 2010 file to C#

Have a look at Excel Data Reader - Read Excel files in .NET[^] and EPPlus[^]

The libraries lets you to import the data, even if Excel is not installed on the computer.

Best regards
Espen Harlinn

you can import data by two method

1) using interop
http://stackoverflow.com/questions/7244971/import-excel-data-into-a-dataset-using-microsoft-office-interop-excel[^]

2)Using oledb
http://stackoverflow.com/questions/10447015/uploading-an-excel-sheet-and-importing-the-data-into-sql-server-database[^]

Google broken?

Interop ring any bells?

Here is a link to one short brief blog about it http://blogs.popart.com/2008/07/importing-data-from-excel-with-c/[^].

I am sure you will find many more better articles if you apply a bit of effort. You could have found these in the time it took you to ask such an open question.

http://code.msdn.microsoft.com/office/Imoprt-Data-from-Excel-to-705ecfcd[^]

Here, try out: http://www.dotnetthoughts.net/import-data-from-excel-using-c-part-2/[^]

Just save it as csv
and import it as string[] lines =File.readAllLines("path.csv");

Here is a good way to read both csv and Excel.
https://toxy.codeplex.com/wikipage?title=Load%20Excel%20into%20DataSet%20with%20Toxy

You can try the below:

string path = fileuploadExcel.PostedFile.FileName;
           string excelConnectionString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + path + ";Extended Properties=Excel 12.0;Persist Security Info=False";
              InsertExceldata(excelConnectionString);
             
           }

In InsertExceldata method do what you desire with the imported data.