Hashtable with MultiDimensional Key in C#

I think a better approach is to encapsulate the many fields of your multi-dimensional key into a class / struct. For example

struct Key {
  public readonly int Dimension1;
  public readonly bool Dimension2;
  public Key(int p1, bool p2) {
    Dimension1 = p1;
    Dimension2 = p2;
  }
  // Equals and GetHashCode ommitted
}

Now you can create and use a normal HashTable and use this wrapper as a Key.