If you just want to get the directories, then the System.IO namespace would be your friend. You can read the directories and inside each directory you can get the files.
http://msdn.microsoft.com/en-us/library/system.io(v=vs.110).aspx[
^] (System.IO at MSDN)
You can use this code, to enumerate the directories inside your file system.
List<string> dirs = new List<string>(Directory.EnumerateDirectories(dirPath));
foreach (string dir in dirs)
{
Console.WriteLine(dir);
Response.Write(dir);
}
After this, you can get the files in that directory.
List<string> files = new List<string>(Directory.EnumerateFiles(dirPath));
foreach (string file in files)
{
Console.WriteLine(file);
Response.Write(file);
}
..repeat the same process for each of the directory and handle the event of Click for each element that contains the name of the next directory.