c# - 配置 Unity 以解析构造函数参数和接口(interface)

Question

我有一个带有两个构造函数参数的 FaxService 类。

public FaxService(string phone, IFaxProvider faxProvider)

Unity 如何配置为第一个参数发送字符串，第二个参数发送 IFaxProvider 实例？我意识到我可以注入(inject)另一个提供字符串的服务，但我正在寻找一个解决方案，我不必更改 FaxService 构造函数参数。

这就是我目前所拥有的...

class Program
{
    static void Main(string[] args)
    {
        var container = new UnityContainer();

        var phone = "214-123-4567";
        container.RegisterType<IFaxProvider, EFaxProvider>();
        container.RegisterType<IFaxService, FaxService>(phone);

        var fax = container.Resolve<IFaxService>();
    }
}

public interface IFaxService { }

public interface IFaxProvider { }

public class FaxService : IFaxService
{
    public FaxService(string phone, IFaxProvider faxProvider) { }
}

public class EFaxProvider : IFaxProvider { }

但是它抛出...

Unity.Exceptions.ResolutionFailedException HResult=0x80131500
Message=Resolution of the dependency failed, type = 'ConsoleApp3.IFaxService', name = '(none)'. Exception occurred while: while resolving.

Answer 1

var container = new UnityContainer();
var phone = "214-123-4567";
container.RegisterType<IFaxProvider, EFaxProvider>();
container.RegisterType<IFaxService, FaxService>(new InjectionConstructor(phone, typeof(IFaxProvider)));

var fax = container.Resolve<IFaxService>();