How can I create temporary objects to pass around without explicitly creating a class?

Question

I frequently find myself having a need to create a class as a container for some data. It only gets used briefly yet I still have to create the class. Like this:

public class TempObject
{
    public string LoggedInUsername { get; set; }
    public CustomObject SomeCustomObject { get; set; }
    public DateTime LastLoggedIn { get; set; }
}


public void DoSomething()
{
    TempObject temp = new TempObject
    {
        LoggedInUsername = "test",
        SomeCustomObject = //blah blah blah,
        LastLoggedIn = DateTime.Now
    };
    DoSomethingElse(temp);
}

public void DoSomethingElse(TempObject temp)
{
    // etc...
}

Usually my temporary objects have a lot more properties, which is the reason I want to group them in the first place. I wish there was an easier way, such as with an anonymous type. The problem is, I don't know what to accept when I pass it to another method. The type is anonymous, so how am I supposed to accept it on the other side?

public void DoSomething()
{
    var temp = new
    {
        LoggedInUsername = "test",
        SomeCustomObject = //blah blah,
        LastLoggedIn = DateTime.Now
    };
    // I have intellisense on the temp object as long as I'm in the scope of this method.
    DoSomethingElse(temp);
}

public void DoSomethingElse(????)
{
    // Can't get my anonymous type here. And even if I could I doubt I would have intellisense.
}

Is there a better way to create a temporary container for a bunch of different types, or do I need to define classes every time I need a temporary object to group things together?

Thanks in advance.

Answer 1

Tuple may be the solution you're looking for.

public void DoSomething() 
{
    var temp = Tuple.Create("test", "blah blah blah", DateTime.Now);
    DoSomethingElse(temp);
}

public void DoSomethingElse(Tuple<string, string, DateTime> data)
{
    // ...
}

Answer 2

The rules state that

You cannot declare a field, a property, an event, or the return type of a method as having an anonymous type. Similarly, you cannot declare a formal parameter of a method, property, constructor, or indexer as having an anonymous type.

Personally, I would just bite the bullet on this one to preserve compile time integrity.

Answer 3

The Tuple is the clean way to go, but just to let you know that C# doesn't let you down even otherwise and to answer the question, this is how DoSomethingElse could look like:

private static void DoSomething(object temp)
        {
            var typedTemp = CastToType(temp, new
                            {
                                LoggedInUsername = "dummy",
                                SomeCustomObject = "dummy",
                                LastLoggedIn = DateTime.Now
                            });

            Console.WriteLine(typedTemp.LastLoggedIn);
        }

private static T CastToType<T>(object obj, T type)
        {
            return (T) obj;
        }

PS: Don't -1, I won't use this, I don't ask you to use this :)