使用 Ninject 进行多重依赖注入的问题

Question

作为免责声明，我想说的是，我仍在尝试理解整个 DI 模式，因此我想不用说我的代码可能存在重大概念性错误。

有了这个，我想做的是在以下实现中注入两个属性：

interface ISurface
{
    string Use();
}

class Canvas : ISurface
{
    public string Use()
    {
        return "canvas";
    }
}

class Hardboard : ISurface
{
    public string Use()
    {
        return "hardboard";
    }
}

interface IMaterial
{
    string Apply(string surface);
}

class Oil : IMaterial
{
    public string Apply(string surface)
    {
        return "painted with oil on {0}";
    }
}

class Acrylic : IMaterial
{
    public string Apply(string surface)
    {
        return "painted with acrylic on {0}";
    }
}

class Artist
{
    public string Name { get; set; }

    [Inject]
    public IMaterial Material { get; set; }

    [Inject]
    public ISurface Surface { get; set; }

    public string Paint()
    {
        return Material.Apply(Surface.Use());
    }
}

class PainterModule : NinjectModule
{
    public override void Load()
    {
        Bind<ISurface>().To<Canvas>();
        Bind<IMaterial>().To<Oil>();
        Bind<Artist>().ToSelf();
    }
}

所以当我调用该方法时：

class Program
{
    static void Main(string[] args)
    {
        try
        {
            IKernel kernel = new StandardKernel(new PainterModule());
            Artist artist = kernel.Get<Artist>();
            artist.Name = "Peter Gibbons";
            Console.WriteLine(artist.Name + artist.Paint());
        }
        catch (Exception error)
        {
            Console.WriteLine(error.Message);
            throw;
        }
        finally
        {
            Console.ReadKey(true);
        }
    }
}

令我惊讶的是它输出：

"Peter Gibbons painted with oil on {0}"

Answer 1

看起来一切都解决得很好，但是您的意思是让 Oil.Apply() 使用 string.Format() 吗？

class Oil : IMaterial
{
    public string Apply(string surface)
    {
        return string.Format("painted with oil on {0}", surface);
    }
}

这应该返回“Peter Gibbons 用油画在画布上画的”。