小编典典

依赖注入统一性-条件解析

有条件的解决是我目前不了解的最后一件事。

可以说我们有一个接口IAuthenticate：

public interface IAuthenticate{
    bool Login(string user, string pass);
}

现在，我有两种身份验证。

Twitter身份验证

public class TwitterAuth : IAuthenticate
{
  bool Login(string user, string pass)
{
   //connect to twitter api
}

}

Facebook身份验证

public class FacebookAuth: IAuthenticate
{
  bool Login(string user, string pass)
{
   //connect to fb api
}

}

在unity config中注册类型：

unityContainer.RegisterType<IAuthenticate, TwitterAuth>();
unityContainer.RegisterType<IAuthenticate, FacebookAuth>();

通过DI在我们的控制器中注入对象：

private readonly IAuthenticate _authenticate;

public AuthenticateController(IAuthenticate authenticate)
{
    _authenticate = authenticate;
}



// login with twitter
public virtual ActionResult Twitter(string user, string pass)
{
    bool success =
            _authenticate.Login(user, pass);
}



// login with fb
public virtual ActionResult Facebook(string user, string pass)
{
    bool success =
            _authenticate.Login(user, pass);
}



// login with google
public virtual ActionResult Google(string user, string pass)
{
    bool success =
            _authenticate.Login(user, pass);
}

统一将如何确切地知道针对不同类型的身份验证必须解决的对象？在这种情况下，我该如何进行条件解析？

我和我的一个朋友交谈，他解释了这种情况是否是错误的设计，但这只是出厂模式。

阅读 340

2020-05-19

共1个答案

小编典典

解决此问题的一种简单方法是使用策略模式。请注意，您可以添加或删除登录提供程序而无需更改设计-
您只需要更改DI配置即可。

介面

public interface IAuthenticate{
    bool Login(string user, string pass);
    bool AppliesTo(string providerName);
}

public interface IAuthenticateStrategy
{
    bool Login(string providerName, string user, string pass);
}

验证提供者

public class TwitterAuth : IAuthenticate
{
    bool Login(string user, string pass)
    {
        //connect to twitter api
    }

    bool AppliesTo(string providerName)
    {
        // I used the type name for this example, but
        // note that you could use any string or other
        // datatype to select the correct provider.
        return this.GetType().Name.Equals(providerName);
    }
}

public class FacebookAuth: IAuthenticate
{
    bool Login(string user, string pass)
    {
        //connect to fb api
    }

    bool AppliesTo(string providerName)
    {
        return this.GetType().Name.Equals(providerName);
    }
}

战略

public class AuthenticateStrategy: IAuthenticateStrategy
{
    private readonly IAuthenticate[] authenticateProviders;

    public AuthenticateStrategy(IAuthenticate[] authenticateProviders)
    {
        if (authenticateProviders == null)
            throw new ArgumentNullException("authenticateProviders");

        this.authenticateProviders = authenticateProviders;
    }

    public bool Login(string providerName, string user, string pass)
    {
        var provider = this.authenticateProviders
            .FirstOrDefault(x => x.AppliesTo(providerName));

        if (provider == null)
        {
            throw new Exception("Login provider not registered");
        }

        return provider.Login(user, pass);
    }
}

统一注册

// Note that the strings used here for instance names have nothing 
// to do with the strings used to select the instance in the strategy pattern
unityContainer.RegisterType<IAuthenticate, TwitterAuth>("twitterAuth");
unityContainer.RegisterType<IAuthenticate, FacebookAuth>("facebookAuth");
unityContainer.RegisterType<IAuthenticateStrategy, AuthenticateStrategy>(
    new InjectionConstructor(
        new ResolvedArrayParameter<IAuthenticate>(
            new ResolvedParameter<IAuthenticate>("twitterAuth")
        ),
        new ResolvedArrayParameter<IAuthenticate>(
            new ResolvedParameter<IAuthenticate>("facebookAuth")
        )
    ));

用法

private readonly IAuthenticateStrategy _authenticateStrategy;

public AuthenticateController(IAuthenticateStrategy authenticateStrategy)
{
    if (authenticateStrategy == null)
        throw new ArgumentNullException("authenticateStrategy");

    _authenticateStrategy = authenticateStrategy;
}



// login with twitter
public virtual ActionResult Twitter(string user, string pass)
{
    bool success =
            _authenticateStrategy.Login("TwitterAuth", user, pass);
}



// login with fb
public virtual ActionResult Facebook(string user, string pass)
{
    bool success =
            _authenticateStrategy.Login("FacebookAuth", user, pass);
}

2020-05-19