プロパティ/フィールド インジェクション

If the object has a local default and Inject is optional, Property/Field Injection can be used.

class ClassA
{
    [Inject]
    IServiceA serviceA { get; set; } // Will be overwritten if something is registered.

    public ClassA()
    {
        serviceA = ServiceA.GoodLocalDefault;
    }
}

It can resolve like this:

    [Inject]
    IServiceA serviceA;