Creating a multi-dimensional hashtable with generics in VB ASP.NET?

Question

I need to create a multi-dimensional (nested) hashtable/dictionary so that I can use syntax like

val = myHash("Key").("key")

I know I need to use Generics but I can't figure out the correct syntax using VB in ASP.NET 2.0, there are plenty of c# examples on the net but they aren't helping much.

Cheers!

Answer 1

OK, I'm better at C# than vb.net, but I'll give this a go....

Dim myHash as Dictionary(Of string, Dictionary(Of string, Integer));

Answer 2

There's also the System.Collections.Specialized.StringDictionary(Of T) collection, which is just a pre-defined Dictionary(Of String, T).

And the syntax to use either the normal Dictionary or the StringDictionary would look like this:

val = myHash("key")("key")

Not like this:

val = myHash("key").("key")

Answer 3

Consider that you may only need to use Dictionary, and that can compose your multiple keys into a single key object with its own composite hash code. E.g. make a multikey class and then use it as the key.

in pseudocode:

class Multikey {
 private keys;
 public setKey1(...)
 public setKey2(...)
}
Dim myKey as MultiKey(...)
myKey.key1 = ...
myKey.key2 = ...

Dim mydic as Dictionary(Of MultiKey, Integer)

val = mydic(myKey)