The simple way to convert Hashtable keys or values into an ArrayList is to use a constructor that takes a list of values. The Hashtable.Keys and Hashtable.Values properties both return a System.Collections.ICollection—and one ArrayList constructor accepts a System.Collections.ICollection. Here's the code to make the conversion in C#:

// Convert Hashtable keys into an arraylist
ArrayList list1 = new ArrayList(hashTable.Keys);


// Convert Hashtable values into an arraylist
ArrayList list2 = new ArrayList(hashTable.Values);