Question

我特意在Ninject中使用C＃，但问题不仅仅是Ninject。我的问题是我有几个类都有不同的构造函数参数加上注入的类。我知道我可以使用kernel.Get<MyObject>(constructor args here)来实例化对象。这对我来说并不合适，因为我的内核遍布整个地方。我将尽力列出以下示例。

我现在拥有的：

public interface IStore<T>
{
    void CommitToDatabase(T item);
}

public abstract class Thing
{
    private IStore<Thing> _store;

    protected Thing(object key, IStore<Thing> store)
    {
        Key = key;
        _store = store;
    }

    public object Key { get; private set; }

    public virtual void Update()
    {
        _store.CommitToDatabase(this);
    }
}

public class Person :Thing
{
    public Person(object key, string name, int age, IStore<Thing> store)
        : base(key, store)
    {
        Name = name;
        Age = age;
    }

    public string Name { get; private set; }
    public int Age { get; private set; }
}

public class Car :Thing
{
    public Car(object key, int year, string make, string model, IStore<Thing> store)
        : base(key, store)
    {
        Year = year;
        Make = make;
        Model = model;
    }

    public int Year { get; private set; }    
    public string Make { get; private set; }
    public string Model { get; private set; }
}

我知道在Ninject我可以做到以下几点：

kernel.Get<Car>(new ConstructorArgument("key", 1), new ConstructorArgument("year", 2010), new ConstructorArgument("make", "Astin Martin"), new ConstructorArgument("model", "Vanquish"));

但这对我来说不合适。我想要做的是将其更改为具有Initialize方法，但我不确定这是最佳实践还是有更好的方法。

可能的新东西：

public interface IStore<T>
{
    void CommitToDatabase(T item);
}

public abstract class Thing
{
    private IStore<Thing> _store;

    protected bool _isInitialised;

    protected Thing(IStore<Thing> store)
    {
        Key = null;
        _store = store;
        _isInitialised = false;
    }

    public object Key { get; private set; }

    public virtual void Initialize(object key)
    {
        if (!_isInitialised) {
            Key = key;
            _isInitialised = true;
        }
    }

    public virtual void Update()
    {
        _store.CommitToDatabase(this);
    }

    protected bool IsInitialised()
    {
        return _isInitialised;
    }
}

public class Person :Thing
{
    public Person(IStore<Thing> store)
        : base(store)
    {
        Name = string.Empty;
        Age = int.MinValue;
    }

    public string Name { get; private set; }
    public int Age { get; private set; }

    public void Initialize(object key, string name, int age)
    {
        if (!base.IsInitialised()) {
            Name = name;
            Age = age;
        }

        base.Initialize(key);
    }
}

public class Car :Thing
{
    public Car(IStore<Thing> store)
        : base(store)
    {
        Year = 0;
        Make = "Ford";
        Model = "Model T";
    }

    public int Year { get; private set; }
    public string Make { get; private set; }
    public string Model { get; private set; }

    public void Initialize(object key, int year, string make, string model)
    {
        if (!base.IsInitialised()) {
            Year = year;
            Make = make;
            Model = model;
        }

        base.Initialize(key);
    }
}

问题： “可能的新东西”是一种常见的做法，糟糕的想法，好的想法和糟糕的实施，还是有更好的方法来完成它？

Answer 1

你不应该将IStore注入你的DTO。它们应该是普通的物体。而是将IStore<IThing>注入当前调用Update的类并从那里调用CommitToDatabase。

e.g。

public class PersonService
{
    private readonly IStore<Person> store;
    public PersonService(IStore<Person> store)
    {
       this.store = store;
    }

    public void CreatePerson(string name, int age)
    {
       var person = new Person(name, age);
       this.store.CommitToDatabase(person);
    }
}

也不应使用IoC容器创建像Person这样的DTO。从持久层获取它们，使用AutoMapper创建它们或使用new创建它们。但是不要为它们使用IoC容器。他们不应该有任何依赖。

依赖注入的创建模式

1 个答案: