Given a class with several constructors - how can I tell Resolve which constructor to use?

Consider the following example class:

public class Foo
{
    public Foo() { }
    public Foo(IBar bar)
    {
        Bar = bar;
    }
    public Foo(string name, IBar bar)
    {
        Bar = bar;
        Name = name;
    }
    public IBar Bar { get; set; }        
    public string Name { get; set; }
}

If I want to create an object of type Foo using Resolve how will Resolve know which constructor to use? And how can I tell it to use the right one? Let's say I have a container with an IBar registered - will it understand that it should favor the constructor taking IBar? And if I specify a string too - will it use the (string, IBar) constructor?

Foo foo = unityContainer.Resolve<Foo>(); 

And please ignore the fact that it would probably be easier if the class just had a single constructor...