Ninject:将接口绑定到多个实现

本文关键字:实现 绑定 接口 Ninject | 更新日期: 2023-09-27 18:32:58

我有一个名为IXMLModelsRepository的接口,我有一个名为XMLModelsRepository的具体实现,它只是从XML文件中读取。

但是,我想改进功能,并且我想将元素临时缓存到Dictionary<>列表中。

我不想修改现有的XMLModelsRepository,但我想创建一个在上面添加缓存功能的新类。

如何使用Ninject接口绑定到两个具体实现?

// the interface i am working with
public interface IXMLModelsRepository
{
    Product GetProduct(Guid entity_Id);
}
// concrete implementation that reads from XML document
public class XMLModelsRepository : IXMLModelsRepository
{
    private readonly XDocument _xDoc = LoadXMLDocument();
    public Product GetProduct(Guid entity_Id)
    {
        return _xDoc.Element("root").Elements("Product").Where(p => p.Attribute("Entity_Id").Value == entity_Id.ToString();
    }
}
// concrete implementation that is only responsable of caching the results
//    this is the class that i will use in the project,
//    but it needs a parameter of the same interface type
public class CachedXMLModelsRepository : IXMLModelsRepository
{
    private readonly IXMLModelsRepository _repository;
    public CachedXMLModelsRepository(
        IXMLModelsRepository repository)
    {
        _repository = repository;
    }
    private readonly Dictionary<Guid, Product> cachedProducts = new Dictionary<Guid, Product>();
    public Product GetProduct(Guid entity_Id)
    {
        if (cachedProducts.ContainsKey(entity_Id))
        {
            return cachedProducts[entity_Id];
        }
        Product product = _repository.GetProduct(entity_Id);
        cachedProducts.Add(entity_Id, product);
        return product;
    }
}

Ninject:将接口绑定到多个实现

您可以使用

WhenInjectedExactlyInto结构。

kernel.Bind<IXMLModelsRepository >().To<CachedXMLModelsRepository>();
kernel.Bind<IXMLModelsRepository >().To<XMLModelsRepository>()
    .WhenInjectedExactlyInto(typeof(CachedXMLModelsRepository));

在上面的示例中,Ninject 将使用缓存的实例进行接口的所有查找,但在构造缓存存储库时,它将注入非缓存对象。