开发者

Multiple constructor with Structuremap changing the scope?

开发者 https://www.devze.com 2022-12-20 22:42 出处:网络
To illustrate the problem, here is a simplified version of my setup. I have a factory like this one :

To illustrate the problem, here is a simplified version of my setup. I have a factory like this one :

public interface IFactory{ }

public class Factory : IFactory
{
    public Factory()
    {
        Console.WriteLine("parameterless");
    }

    //public Factory(int i)
    //{
    //    Console.WriteLine("with parameter : {0}", i);
    //}

}

the program to test this is a consoleApp. Enough to prove my point.

static void Main(string[] args)
{
     Init();
     var factory1 = ObjectFactory.GetInstance<IFactory>();
     var factory2 = ObjectFactory.GetInstance<IFactory>();
     var factory3 = ObjectFactory.GetInstance<IFactory>();
     开发者_如何学GoConsole.Read();
 }

I setup strucutreMap in my Init static method.

  public static void Init()
        {
            ObjectFactory.Initialize(x =>
            {
                 //insert Initialization code here.
            });
        }

If I have only one constructor and setup StructureMap like this :

x.For<IFactory>().Use<Factory>();

that works perfect, and the output shows

parameterless

parameterless

parameterless

Each call builds a new instance.

Now if I uncomment the second constructor, but I want to use the parameterless one, and with the same default lifestyle. How would I do?

I tried that :

x.SelectConstructor<IFactory>(() => new Factory());
x.For<IFactory>().Use<Factory>();

It just doesn't work : Missing requested Instance property "i" for InstanceKey

If I do like this :

 x.For<IFactory>().Use(new Factory());

It works, but the output is just one "parameterless" meaning it's not building a new instance for each call. It's using this specific instance I pass in.

The only way I found is to add the [DefaultConstructor] on top of my parameterless constructor and use the standard x.For().Use(); But I don't want to add this attribute and spread the configuration accross my model.

Help?


SelectConstructor takes the concrete type, not the interface. Of course, an interface doesnt have any constructor. But nothing breaks, it's just ignored.... so I couldnt spot that error.

 x.SelectConstructor<IFactory>(() => new Factory());
 x.For<IFactory>().Use<Factory>();

should be

 x.SelectConstructor<**Factory**>(() => new Factory());
 x.For<IFactory>().Use<Factory>();
0

精彩评论

暂无评论...
验证码 换一张
取 消

关注公众号