Exporting GridView to Excel file is a common task for almost all ASP.NET applications that involves displaying reports of data to users. Usually the report from the screen must be exported to different file formats. The Excel file formats, like XLS, XLSX, XLSM and XLSB, are some of them.

EasyXLS Excel library lets you export the GridView in a very simple and fast way and it allows you to format the report according to requirements.

The library can be integrated in ASP.NET web applications and can be used from C#, VB.NET or C++.NET.

The exported Excel file can have multiple sheets and each of them can contain another GridView, if necessary, or additional data.

EasyXLS allows you to export the GridView and the Excel file will have a similar look like your screen report. The library offers all the formatting features for the Excel cells including background, foreground, borders and alignment options. The data from the Excel cells can be locked from unintentional editing events. Even more, the exported Excel file can be password secured when the file is opened or edited.

EasyXLS handles very well big volume of data and it works without Excel installed and without OLE Automation.

Check here some source code samples:
Export GridView to Excel in C#
Export GridView to Excel in VB.NET