GridView Sorting Question

I have an exisiting gridview that I need to fix/improve here at work. Basically the GridView has headings and they are being binded by a data set in the code behind, it uses BoundFields and TemplateFields. The problem is that I am needed to make each column sortible. What would be the best approach to do this since it is not the standard gridview?, I need to make the header links and when click to sort in DESC or ASC order. Here is an example of the gridview I need to work on.

Generate a unique id

I am a student at university and our task is to create a search engine. I am having difficulty generating a unique id to assign to each url when added into the frontier. I have attempted using the SHA-256 hashing algorithm as well as Guid. Here is the code that i used to implement the guid: