如何使用Castle Windsor注册通用装饰器？

Question

我需要使用相应的DeadlockRetryCommandHandlerDecorator<T>类型基于ICommandHandler<T>类型来装饰所有类型

我试过这个解决方案，但遗憾的是它不起作用。

container.Register(
    Component.For(typeof(ICommandHandler<>))
    .ImplementedBy(typeof(DeadlockRetryCommandHandlerDecorator<>)));

container.Register(
    AllTypes.FromThisAssembly()
        .BasedOn(typeof(ICommandHandler<>))
        .WithService.Base());

如何注册通用装饰器（ DeadlockRetryCommandHandlerDecorator<T> ）来包装所有通用ICommandHandler<T>实现？

Answer 1

目前这不支持OOTB，因为Windsor总是倾向于特定于模式的组件而不是开放式泛型。

但是，使用ISubDependencyResolver可以很容易地实现这ISubDependencyResolver 。 下面的代码假设您为装饰器"DeadlockRetryCommandHandlerDecorator"命名组件

public class CommandHandlerResolver : ISubDependencyResolver
{
    private readonly IKernel kernel;

    public FooResolver(IKernel kernel)
    {
        this.kernel = kernel;
    }

    public bool CanResolve(CreationContext context, ISubDependencyResolver contextHandlerResolver, ComponentModel model, DependencyModel dependency)
    {
        return (dependency.TargetType.IsGenericType &&
                dependency.TargetType.GetGenericTypeDefinition() == typeof (ICommandHandler<>)) &&
                (model.Implementation.IsGenericType == false ||
                model.Implementation.GetGenericTypeDefinition() != typeof (DeadlockRetryCommandHandlerDecorator<>));
    }

    public object Resolve(CreationContext context, ISubDependencyResolver contextHandlerResolver, ComponentModel model, DependencyModel dependency)
    {
        return kernel.Resolve("DeadlockRetryCommandHandlerDecorator", dependency.TargetItemType);
    }
}

然而，使用拦截器来实现与Windsor一样的场景的推荐方法。

Answer 2

我遇到过同样的问题。 我设法通过将每种类型明确注册为更具体的类型来解决它。 对我来说，这个解决方案比使用子依赖解析器更清晰

var commandTypes = businessAssembly.GetTypes()
    .Where(t => !t.IsInterface && typeof(ICommand).IsAssignableFrom(t));

foreach(var commandType in commandTypes)
{
    var handlerInterface = typeof(ICommandHandler<>).MakeGenericType(new[] { commandType });
    var transactionalHandler = typeof(DeadlockRetryCommandHandlerDecorator<>).MakeGenericType(new[] { commandType });
    container.Register(Component.For(handlerInterface)
        .ImplementedBy(transactionalHandler)
        .LifeStyle.PerWebRequest);
}