依赖注入的创建模式

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kernel.Get<MyObject>(constructor args here)用来实例化对象.这对我来说并不合适,因为我的内核遍布整个地方.我会尽力列出下面的例子.

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"));

但这对我来说并不合适.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

你不应该把IStore注入你的DTO.它们应该是普通的物体.而是注入IStore<IThing>当前从那里调用Update和调用的类CommitToDatabase.

例如

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);
    }
}

此外,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创建它们或使用它们创建它们new.但是不要为它们使用IoC容器.他们不应该有任何依赖.