export , zip and save file using c# web-based problem

i am developing a problem using asp.net & c#
and i would like to build a export function. just click one button i need to export the data to text file and finally zip all the text file into a zip file and save to client local pc.
for example, user click the export button, the function export 10 txt files. and finally zip the 10 files into 1 zip file and save.
any code reference for me ?
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