AutoFac是.net平臺下的IOC容器產品，它可以管理類之間的複雜的依賴關係。在使用方面主要是register和resolve兩類操作。 這篇文章用單元測試的形式列舉了AutoFac的常用使用方法： 註冊部分 使用RegisterType進行註冊 註冊為介面 使用lambda表達式進行註冊 帶構 ...
AutoFac是.net平臺下的IOC容器產品，它可以管理類之間的複雜的依賴關係。在使用方面主要是register和resolve兩類操作。 這篇文章用單元測試的形式列舉了AutoFac的常用使用方法：
註冊部分
使用RegisterType進行註冊
1 [Fact]
2 public void can_resolve_myclass()
3 {
4 var builder = new ContainerBuilder();
5 builder.RegisterType<MyClass>();
6
7 IContainer container = builder.Build();
8 var myClass = container.Resolve<MyClass>();
9 Assert.NotNull(myClass);
10 }
註冊為介面
1 [Fact]
2 public void register_as_interface()
3 {
4 var builder = new ContainerBuilder();
5 builder.Register(c => new MyClass()).As<MyInterface>();
6
7 IContainer container = builder.Build();
8 Assert.NotNull(container.Resolve<MyInterface>());
9 Assert.Throws(typeof (ComponentNotRegisteredException), () => container.Resolve<MyClass>());
10 }
使用lambda表達式進行註冊
1 [Fact]
2 public void can_register_with_lambda()
3 {
4 var builder = new ContainerBuilder();
5 builder.Register(c => new MyClass());
6
7 IContainer container = builder.Build();
8 var myClass = container.Resolve<MyClass>();
9 Assert.NotNull(myClass);
10 }
帶構造參數的註冊
1 [Fact]
2 public void register_with_parameter()
3 {
4 var builder = new ContainerBuilder();
5 builder.Register(c => new MyParameter());
6 builder.Register(c => new MyClass(c.Resolve<MyParameter>()));
7 IContainer container = builder.Build();
8 Assert.NotNull(container.Resolve<MyClass>());
9 }
帶屬性賦值的註冊
1 [Fact]
2 public void register_with_property()
3 {
4 var builder = new ContainerBuilder();
5 builder.Register(c => new MyProperty());
6 builder.Register(
7 c => new MyClass()
8 {
9 Property = c.Resolve<MyProperty>()
10 });
11 IContainer container = builder.Build();
12 var myClass = container.Resolve<MyClass>();
13 Assert.NotNull(myClass);
14 Assert.NotNull(myClass.Property);
15 }
Autofac分離了類的創建和使用，這樣可以根據輸入參數（NamedParameter）動態的選擇實現類。
1 [Fact]
2 public void select_an_implementer_based_on_parameter_value()
3 {
4 var builder = new ContainerBuilder();
5 builder.Register<IRepository>((c, p) =>
6 {
7 var type = p.Named<string>("type");
8 if (type == "test")
9 {
10 return new TestRepository();
11 }
12 else
13 {
14 return new DbRepository();
15 }
16 }).As<IRepository>();
17
18 IContainer container = builder.Build();
19 var repository = container.Resolve<IRepository>(new NamedParameter("type", "test"));
20 Assert.Equal(typeof(TestRepository),repository.GetType());
21 }
AufoFac也可以用一個實例來註冊，比如用在單例模式情況下：
1 [Fact]
2 public void register_with_instance()
3 {
4 var builder = new ContainerBuilder();
5 builder.RegisterInstance(MyInstance.Instance).ExternallyOwned();
6 IContainer container = builder.Build();
7 var myInstance1 = container.Resolve<MyInstance>();
8 var myInstance2 = container.Resolve<MyInstance>();
9 Assert.Equal(myInstance1,myInstance2);
10 }
註冊open generic類型
1 [Fact]
2 public void register_open_generic()
3 {
4 var builder = new ContainerBuilder();
5 builder.RegisterGeneric(typeof (MyList<>));
6 IContainer container = builder.Build();
7 var myIntList = container.Resolve<MyList<int>>();
8 Assert.NotNull(myIntList);
9 var myStringList = container.Resolve<MyList<string>>();
10 Assert.NotNull(myStringList);
11 }
對於同一個介面，後面註冊的實現會覆蓋之前的實現
1 [Fact]
2 public void register_order()
3 {
4 var containerBuilder = new ContainerBuilder();
5 containerBuilder.RegisterType<DbRepository>().As<IRepository>();
6 containerBuilder.RegisterType<TestRepository>().As<IRepository>();
7
8 IContainer container = containerBuilder.Build();
9 var repository = container.Resolve<IRepository>();
10 Assert.Equal(typeof(TestRepository), repository.GetType());
11 }
如果不想覆蓋的話，可以用PreserveExistingDefaults，這樣會保留原來註冊的實現。
1 [Fact]
2 public void register_order_defaults()
3 {
4 var containerBuilder = new ContainerBuilder();
5 containerBuilder.RegisterType<DbRepository>().As<IRepository>();
6 containerBuilder.RegisterType<TestRepository>().As<IRepository>().PreserveExistingDefaults();
7
8 IContainer container = containerBuilder.Build();
9 var repository = container.Resolve<IRepository>();
10 Assert.Equal(typeof (DbRepository), repository.GetType());
11 }
可以用Name來區分不同的實現，代替As方法
1 [Fact]
2 public void register_with_name()
3 {
4 var containerBuilder = new ContainerBuilder();
5 containerBuilder.RegisterType<DbRepository>().Named<IRepository>("DB");
6 containerBuilder.RegisterType<TestRepository>().Named<IRepository>("Test");
7
8 IContainer container = containerBuilder.Build();
9 var dbRepository = container.ResolveNamed<IRepository>("DB");
10 var testRepository = container.ResolveNamed<IRepository>("Test");
11 Assert.Equal(typeof(DbRepository), dbRepository.GetType());
12 Assert.Equal(typeof(TestRepository), testRepository.GetType());
13 }
如果一個類有多個構造函數的話，可以在註冊時候選擇不同的構造函數
1 [Fact]
2 public void choose_constructors()
3 {
4 var builder = new ContainerBuilder();
5 builder.RegisterType<MyParameter>();
6 builder.RegisterType<MyClass>().UsingConstructor(typeof (MyParameter));
7 IContainer container = builder.Build();
8 var myClass = container.Resolve<MyClass>();
9 Assert.NotNull(myClass);
10 }
AutoFac可以註冊一個Assemble下所有的類，當然，也可以根據類型進行篩選
1 [Fact]
2 public void register_assembly()
3 {
4 var builder = new ContainerBuilder();
5 builder.RegisterAssemblyTypes(Assembly.GetExecutingAssembly()).
6 Where(t => t.Name.EndsWith("Repository")).
7 AsImplementedInterfaces();
8
9 IContainer container = builder.Build();
10 var repository = container.Resolve<IRepository>();
11 Assert.NotNull(repository);
12 }
參考鏈接：http://niuyi.github.io/blog/2012/04/06/autofac-by-unit-test/
