C＃非整数枚举和转换

Question

C# allows you to assign values to your enum elements such as

public enum Animals
{
    Dog = 0, Cat = 1,
}

And You can cast too and from them like so.

public void demo()
{
    int dog = (int)Animals.Dog;
    Animals cat = (Animals)(dog++);
}

But c# also lets you do things like this

public enum Animals
{
    Dog = Vector2.One, Cat = Vector2.Zero,
}

However you cannot get the Vector2 back in and out with a cast. such as

Vector2 dog = (Vector2)Animals.Dog; //this fails

Is this problem solvable? *Note Vector2 is a class object and Vector2.One and Vector2.Zero are static declarations of such. Which means Dog is assigned to a memory reference.

Answer 1

The only way that C# will let you do

public enum Animals
{
    Dog = Vector2.One,
    Cat = Vector2.Zero
}

Is if there is an implicit cast from Vector2 to an integral type. Otherwise, you will get a compile error. This is why you cannot cast back to Vector2 - there is no cast from int back to Vector2 . Dog and Cat are integer valued, and the values come from the implicit cast from Vector2.One and Vector2.Zero to int , respectively.

You could define your own explicit cast to make it work, but I'm guessing you won't be able to get back all the information you want that way.