使用多个命名空间描述一个类

Question

I am writing code for a game, and wanted to include my main method in two different namespaces so that it could easily access all the classes from both the 'Engine' and 'Core' Namespaces.

namespace Engine Core
{
    class ExampleClass
    {
    }
}

Although I just put a space between Engine and Core, I know that this syntax is incorrect, I would like to know how to make a class a member of multiple namespaces. If this is not possible, is there anything that I could do that would act the same? (Classes in neither these two namespaces having to refer to this class by 'Engine.' or 'Core.'

Answer 1

A class can not belong to two different namespaces. If you want to refer to a class of the Engine or Core namespaces without explicitly writing the namespace each time you reference a type of those namespaces, just use using at the beginning of the file. The using directive allows the use of types in a namespace so that you do not have to qualify the use of a type in that namespace:

using Engine;

or

using Core;

Check the documentation: using Directive

Answer 2

So you want someone to be able to access ExampleClass by using Engine.ExampleClass and Core.ExampleClass ? I'm not sure why you would (I'm sure you have your reasons) but two ways to expose something like this are:

namespace Foo
{
    abstract class ExampleClass
    {
         //Only implement the class here
    }
}

namespace Engine
{
    class ExampleClass : Foo.ExampleClass
    {
         //Don't implement anything here (other than constructors to call base constructors)
    }
}

namespace Core
{
    class ExampleClass : Foo.ExampleClass
    {
         //Don't implement anything here (other than constructors to call base constructors)
    }
}

Or you could use namespace aliasing but every cs file using the class would require the alias to be defined.

using Engine = Core;