Hi... Use below Query to get your desired files type collection:
  1. string FolderPath = @"D:\AllFiles";
  2. DirectoryInfo di = new DirectoryInfo(FolderPath)
  4. //Get All csv Files
  5. List getAllCSVFiles = di.GetFiles("*.csv")
  6. .Where(file => file.Name.EndsWith(".csv"))
  7. .Select(file => file.Name).ToList();
  9. //Get All Notepad Files
  10. List getAllNotePadFiles = di.GetFiles("*.txt")
  11. .Where(file => file.Name.EndsWith(".txt"))
  12. .Select(file => file.Name).ToList();
Just pass your file extension and enjoy