在asp.net中编写和下载xml文件的最佳方式是什么?

I have a web form, that needs to save the data that the user enters, into a file and on the client pc, that will also be able to read from the saved file and repopulate the fields at a later time. No files will be saved to the server side, so I expect streaming needs to be involved at writing time. I have a web form, that needs to save the data