How do you cast an object to a Tuple?

Question

I create my Tuple and add it to a combo box:

comboBox1.Items.Add(new Tuple<string, string>(service, method));

Now I wish to cast the item as a Tuple, but this does not work:

Tuple<string, string> selectedTuple = 
                   Tuple<string, string>(comboBox1.SelectedItem);

How can I accomplish this?

Solution 1

Don't forget the () when you cast:

Tuple<string, string> selectedTuple = 
                  (Tuple<string, string>)comboBox1.SelectedItem;

Solution 2

As of C# 7 you can cast very simply:

var persons = new List<object>{ ("FirstName", "LastName") };
var person = ((string firstName, string lastName)) persons[0];

// The variable person is of tuple type (string, string)

Note that both parenthesis are necessary. The first (from inside out) are there because of the tuple type and the second because of an explicit conversion.

Solution 3

Your syntax is wrong. It should be:

Tuple<string, string> selectedTuple = (Tuple<string, string>)comboBox1.SelectedItem;

Alternatively:

var selectedTuple = (Tuple<string, string>)comboBox1.SelectedItem;

Comments

[Alexandru]

Thanks! I got lost in all the brackets. I'll mark your post as the best answer once the timer expires!

[TYY]

Or Tuple<string, string> selectedTuple = (comboBox1.SelectedItem as Tuple<string, string>);

[Rune FS]

@TYY which will hide an error if for some unexpected reason it's not a tuple. If you know something is of type T then use a cast, if you know that something might be of type T but it's valid bahavior even if it's not use as and a null test

[TYY]

@Rune FS Well depending on how he is using the tuple object, a check on null could make sense vs throwing an exception. Just giving him another option even though I know Cedric's answer is absolutely correct.

[Rune FS]

@TYY yes that's exactly what I state that in the case he knows it should always be the specified tuple type cast is the appropriate option (because if the cast fails it is then by definition an exceptional situation) if the object could legally be something else asis the appropriate option

[Jess Rod]

I'd rather use: var person = ((string, string)) persons[0];

[DomenPigeon]

Yes that's also possible but in this case you you would need to use person.Item1 and person.Item2 instead of person.firstName and person.lastName