How to access value in a Dictionary that has a Tuple as the Key in c#?

Question

I have created a dictionary with Tuples as keys and a enumerator as value.

mKeyValue.Add(Tuple.Create(lineCount,columnID),(E)style);

mKeyValue is the dictionary.

static Dictionary<Tuple<int,int>,E> mKeyValue = new Dictionary<Tuple<int,int>,E>();

Now how to access elements in this dictionary? I used something like this,

mKeyValue[Tuple<lineCount,columnID>];

but it doesn't work.

Answer 1

It's no different than usage with any other type of key. You need to pass an instance of the type, not the type (declaration) itself to the indexer.

You wouldn't say myKeyValue[int] , for a Dictionary<int, ...> , when you really wanted myKeyValue[5] . Just the the key looks a little more "complicated" in this case.

Example:

// Lookup entry for LineCount = 1, ColumnID = 4711
var value = myKeyValue[Tuple.Create(1, 4711)];

Basically, just like you did when adding an entry with Dictionary<>.Add(...) .

Answer 2

If you already have a Tuple<int,int> defined then use that as key like mKeyValue[t];

Tuple<int,int> t = Tuple.Create(1, 1);
mKeyValue.Add(Tuple.Create(1, 1), (E)21);
var data = mKeyValue[t];