AutoFac使用方法总结-白红宇

AutoFac使用方法总结

阅读量：5776 次

发布时间：2019-06-18

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AutoFac是.net平台下的IOC容器产品，它可以管理类之间的复杂的依赖关系。在使用方面主要是register和resolve两类操作。这篇文章用单元测试的形式列举了AutoFac的常用使用方法：

注册部分

使用RegisterType进行注册

                       [Fact]    public void can_resolve_myclass()    {
                  var builder = new ContainerBuilder();        builder.RegisterType
          ();        IContainer container = builder.Build();        var myClass = container.Resolve
           ();        Assert.NotNull(myClass);    }
        
     

注册为接口

                       [Fact]    public void register_as_interface()    {
                  var builder = new ContainerBuilder();        builder.Register(c => new MyClass()).As
          ();        IContainer container = builder.Build();        Assert.NotNull(container.Resolve
           ());        Assert.Throws(typeof (ComponentNotRegisteredException), () => container.Resolve
            ());    }
        
     

使用lambda表达式进行注册

                       [Fact]    public void can_register_with_lambda()    {
                  var builder = new ContainerBuilder();        builder.Register(c => new MyClass());        IContainer container = builder.Build();        var myClass = container.Resolve
          ();        Assert.NotNull(myClass);    }
        
     

带构造参数的注册

                       [Fact]    public void register_with_parameter()    {
                  var builder = new ContainerBuilder();        builder.Register(c => new MyParameter());        builder.Register(c => new MyClass(c.Resolve
          ()));        IContainer container = builder.Build();        Assert.NotNull(container.Resolve
           ());    }
        
     

带属性赋值的注册

                       [Fact]    public void register_with_property()    {
                  var builder = new ContainerBuilder();        builder.Register(c => new MyProperty());        builder.Register(            c => new MyClass()                     {
                                   Property = c.Resolve
          ()                     });        IContainer container = builder.Build();        var myClass = container.Resolve
           ();        Assert.NotNull(myClass);        Assert.NotNull(myClass.Property);    }
        
     

Autofac分离了类的创建和使用，这样可以根据输入参数（NamedParameter）动态的选择实现类。

                       [Fact]    public void select_an_implementer_based_on_parameter_value()    {
                  var builder = new ContainerBuilder();        builder.Register
          ((c, p) =>                             {
                                           var type = p.Named
           ("type");                                 if (type == "test")                                 {
                                               return new TestRepository();                                 }                                 else                                 {
                                               return new DbRepository();                                 }                             }).As
            ();        IContainer container = builder.Build();        var repository = container.Resolve
             (new NamedParameter("type", "test"));        Assert.Equal(typeof(TestRepository),repository.GetType());    }
        
     

AufoFac也可以用一个实例来注册，比如用在单例模式情况下：

                       [Fact]    public void register_with_instance()    {
                  var builder = new ContainerBuilder();        builder.RegisterInstance(MyInstance.Instance).ExternallyOwned();        IContainer container = builder.Build();        var myInstance1 = container.Resolve
          ();        var myInstance2 = container.Resolve
           ();        Assert.Equal(myInstance1,myInstance2);    }
        
     

注册open generic类型

                       [Fact]    public void register_open_generic()    {
                  var builder = new ContainerBuilder();        builder.RegisterGeneric(typeof (MyList<>));        IContainer container = builder.Build();        var myIntList = container.Resolve
           >();        Assert.NotNull(myIntList);        var myStringList = container.Resolve
             >();        Assert.NotNull(myStringList);    }
        
     

对于同一个接口，后面注册的实现会覆盖之前的实现

                       [Fact]    public void register_order()    {
                  var containerBuilder = new ContainerBuilder();        containerBuilder.RegisterType
          ().As
           ();        containerBuilder.RegisterType
            ().As
             ();        IContainer container = containerBuilder.Build();        var repository = container.Resolve
              ();        Assert.Equal(typeof(TestRepository), repository.GetType());    }
        
     

如果不想覆盖的话，可以用PreserveExistingDefaults，这样会保留原来注册的实现。

                       [Fact]    public void register_order_defaults()    {
                  var containerBuilder = new ContainerBuilder();        containerBuilder.RegisterType
          ().As
           ();        containerBuilder.RegisterType
            ().As
             ().PreserveExistingDefaults();        IContainer container = containerBuilder.Build();        var repository = container.Resolve
              ();        Assert.Equal(typeof (DbRepository), repository.GetType());    }
        
     

可以用Name来区分不同的实现，代替As方法

                       [Fact]    public void register_with_name()    {
                  var containerBuilder = new ContainerBuilder();        containerBuilder.RegisterType
          ().Named
           ("DB");        containerBuilder.RegisterType
            ().Named
             ("Test");        IContainer container = containerBuilder.Build();        var dbRepository = container.ResolveNamed
              ("DB");        var testRepository = container.ResolveNamed
               ("Test"); Assert.Equal(typeof(DbRepository), dbRepository.GetType()); Assert.Equal(typeof(TestRepository), testRepository.GetType()); }
        
     

如果一个类有多个构造函数的话，可以在注册时候选择不同的构造函数

                       [Fact]    public void choose_constructors()    {
                  var builder = new ContainerBuilder();        builder.RegisterType
          ();        builder.RegisterType
           ().UsingConstructor(typeof (MyParameter));        IContainer container = builder.Build();        var myClass = container.Resolve
            ();        Assert.NotNull(myClass);    }
        
     

AutoFac可以注册一个Assemble下所有的类，当然，也可以根据类型进行筛选

                       [Fact]    public void register_assembly()    {
                  var builder = new ContainerBuilder();        builder.RegisterAssemblyTypes(Assembly.GetExecutingAssembly()).            Where(t => t.Name.EndsWith("Repository")).            AsImplementedInterfaces();        IContainer container = builder.Build();        var repository = container.Resolve
          ();        Assert.NotNull(repository);    }
        
     