如何使用统一DI仅将一个对象注入构造函数

Question

How to inject only one object to constructor using Unity DI. Example:

public class MyClass{

public MyClass(ILog logger, IProvider provider, IResolver resolver, ItemTypeEnum itemType)
{
   //.... initializing everything
}

public ItemTypeEnum ItemType { get; set;}

//....methods where I will use this itemKind
}

I want to inject only itemType value to the constructor, to use this itemType in implementation depends of value of this enum.

Answer 1

Disclaimer: I might have gotten the question wrong, but to me it only makes sense to inject all dependencies but itemType , not the other way round.

The easiest option is to create a MyClassFactory with a CreateMyClass( ItemTypeEnum itemType ) method. Details see over there ...

Answer 2

You can use InjectionConstructor and provide parameter during the resolution. The example is as following:

container.RegisterType<ILog, Log>();
container.RegisterType<IResolver, Resolver>();
container.RegisterType<IProvider, Provider>();
container.RegisterType<MyClass>(new InjectionConstructor(
    new ResolvedParameter<ILog>(),
    new ResolvedParameter<IProvider>(),
    new ResolvedParameter<IResolver>(),
    typeof(ItemTypeEnum)));                

MyClass mc = container.Resolve<MyClass>(new ParameterOverride("itemType", ItemTypeEnum.Value));