全局名称空间优先于使用名称空间？

Question

I feel like this is a silly question, but I can;t seem to figure out why this is happening. Consider the following:

// file: A.cs
class A {
    public static string ns = "global";
}


// file: myNamespace\A.cs
namespace myNamespace {
    class A {
        public static string ns = "myNamespace";
    }
}


// in some other file...
using myNamespace;

class myClass {
    public void myMethod() {
        Console.WriteLine(A.ns);
    }
}

// OUTPUT: global

Now, since I have declared I want to use myNamespace; why is the compiler stubbornly trying to use the global version instead of the namespaced version? What is the point of using if it is going to do this?

My real code is more complicated than this of course. In the real code I am having the issue in (Unity API), I am getting a compile error in a case more like this:

A myObj = gameObject.GetComponent<A>();

This gives me an argument exception. Not sure if maybe this has to do with generics? Am I missing something very dumb?

Answer 1

I can't test it or find the spec right now, but I believe the resolution rules will search the namespace that the calling code is in first. Since your calling code is in the global namespace, that namespace is searched fist. If you put the calling code inside the myNamespace namespace I suspect you'd get the behavior you are looking for.

If the calling code was not in either namespace then you should get an "ambiguous type" compiler error.

Also note that your classes are internal by default, although if your classes are all in the same assembly that should be an issue.