Unity的构造函数依赖注入提供一种默认的行为，在Resolve一个类型实例时完成依赖注入（这个类型并不一定需要注册，但注入类型需要注册）。看一个简单的示例：
1 public interface IMyInterface 2 { 3 4 } 5 6 public interface IMyInterface2 7 { 8 9 } 10 11 public sealed class MyInterfaceImpl : IMyInterface 12 { 13 14 } 15 16 public sealed class MyInterface2Impl : IMyInterface2 17 { 18 19 } 20 21 public sealed class MyObject 22 { 23 public MyObject(IMyInterface myInterface, IMyInterface2 myInterface2) 24 { 25 26 } 27 } 28 29 IUnityContainer unityContainer = new UnityContainer(); 30 31 unityContainer.RegisterType<IMyInterface, MyInterfaceImpl>(); 32 unityContainer.RegisterType<IMyInterface2, MyInterface2Impl>(); 33 34 MyObject myObject = unityContainer.Resolve<MyObject>();
MyObject的构造函数参数myInterface和myInterface2被注入了MyInterfaceImpl和MyInterface2Impl。如果需要注入特定的类型，可以通过DependencyAttribute指定注册名称。
1 public sealed class MyObject 2 { 3 public MyObject([Dependency("MyInterface")]IMyInterface myInterface, IMyInterface2 myInterface2) 4 { 5 6 } 7 }
当一个类型定义了多个构造函数时，可以通过InjectionConstructorAttribute声明被注入的构造函数。
1 public sealed class MyObject 2 { 3 public MyObject(IMyInterface myInterface) 4 { 5 6 } 7 8 [InjectionConstructor] 9 public MyObject(IMyInterface myInterface, IMyInterface2 myInterface2) 10 { 11 12 } 13 }