Setting Hyperlinks In Order For Users To Carry Out Forced Downloads?

I am using Microsoft's MVC design pattern and I have a method in my controller, which sets the data source of a gridview. Whilst I can bind all the other values in the gridview, I am stuck setting 4 hyperlinks. The hyperlinks need to work in the explanation given in the link below: [URL]for forcing downloads to keep the location of where files are saved to private, which I want set in the controller.

To fully explain what I am doing, in my controller for the gridview, I am setting the gridview's data source using ICollection, which is an object containing results from a query. From this collection, I extract a value which has the name of a folder which contains a number files. So, what I have done is to cast my collection to a object, to get folder name and then use a foreach loop to get each folder name. Then to get the files inside each folder, I use Directory.GetFiles, which returns a string array - I wrote string[] files = Directory.GetFiles(ConfigurationManager.appsettings["filepath"]+folderName); . I have set 4 properties for each Hyperlink I want to set.

It is at this point where I am stuck, because even though I can get to the files, I am unable to set the Hyperlinks to these files. Each time I try an set the NavigateUrl property, I get the error message Object not set to an instance of an object. Plus, I have two other issues to resolve:1) Even though there are 4 hyperlinks, not every hyperlink will be set. In other words, if there are only two files in the folder, I only want to set the appropriate hyperlinks. So, how can I iterate through the string array, and get each value inside the array to do a check?2) When I set my Hyperlinks in my controller, how do I simply pass the file and keep the file's actual storage location hidden as given in the link [URL]