Question

如果我有：

container.RegisterType<ICalculationBuilder, CalculationBuilder>();

我知道每次解析ICalculationBuilder时都会得到一个新实例。

我知道如果这样做：

var childContainer = container.CreateChildContainer();

childContainer.RegisterType<ICalculationBuilder, CalculationBuilder>(new HierarchicalLifetimeManager());

然后，每次在该子范围内解析ICalculationBuilder时，我都会获得相同的实例。

但是给出了：

class CalculationBuilder
{
  CalculationBuilder(int year)
  {
  }
}

如何为每年获得一个不同的CalculationBuilder实例？所以，如果我这样做：

var builder1 = childContainer.Resolve(typeof(ICalculationBuilder), new DependencyOverride<int>(2017));

var builder2 = childContainer.Resolve(typeof(ICalculationBuilder), new DependencyOverride<int>(2017));

var builder3 = childContainer.Resolve(typeof(ICalculationBuilder), new DependencyOverride<int>(2018));

然后

Assert.Same(builder1, builder2) would be true

和

Assert.NotSame(builder2, builder3) would be false

Answer 1

我认为，您可以创建某种工厂来管理您的对象：

class CalculationFactory : IDisposable
{
    private readonly Dictionary<int, CalculationBuilder> cache = new Dictionary<int, CalculationBuilder>();
    private readonly IUnityContainer container;

    public ICalculationBuilder Get(int year)
    {
        if (!cache.ContainsKey(year))
        {
            cache[year] = container.Resolve(typeof(ICalculationBuilder), new DependencyOverride<int>(year));
        }

        return cache[year];
    }

    public void Dispose()
    {
        cache.Clear();
    }
}

仅通过此类创建对象。它会缓解每年的失误。

Unity - 如何有条件地创建子范围？

1 个答案: