Autofac-注册多个装饰器
本文关键字:注册 Autofac- | 更新日期: 2023-09-27 18:20:44
给定以下条件:
public interface ICommandHandler<in TCommand>
{
void Handle(TCommand command);
}
public class MoveCustomerCommand
{
}
public class MoveCustomerCommandHandler : ICommandHandler<MoveCustomerCommand>
{
public void Handle(MoveCustomerCommand command)
{
Console.WriteLine("MoveCustomerCommandHandler");
}
}
public class TransactionCommandHandlerDecorator<TCommand> : ICommandHandler<TCommand>
{
private readonly ICommandHandler<TCommand> _decorated;
public TransactionCommandHandlerDecorator(ICommandHandler<TCommand> decorated)
{
_decorated = decorated;
}
public void Handle(TCommand command)
{
Console.WriteLine("TransactionCommandHandlerDecorator - before");
_decorated.Handle(command);
Console.WriteLine("TransactionCommandHandlerDecorator - after");
}
}
public class DeadlockRetryCommandHandlerDecorator<TCommand> : ICommandHandler<TCommand>
{
private readonly ICommandHandler<TCommand> _decorated;
public DeadlockRetryCommandHandlerDecorator(ICommandHandler<TCommand> decorated)
{
_decorated = decorated;
}
public void Handle(TCommand command)
{
Console.WriteLine("DeadlockRetryCommandHandlerDecorator - before");
_decorated.Handle(command);
Console.WriteLine("DeadlockRetryCommandHandlerDecorator - after");
}
}
我可以使用以下代码用TransactionCommandHandlerDecorator
装饰MoveCustomerCommandHandler
:
var builder = new ContainerBuilder();
builder.RegisterAssemblyTypes(typeof(MoveCustomerCommandHandler).Assembly)
.As(type => type.GetInterfaces()
.Where(interfaceType => interfaceType.IsClosedTypeOf(typeof(ICommandHandler<>)))
.Select(interfaceType => new KeyedService("commandHandler", interfaceType)));
builder.RegisterGenericDecorator(
typeof(TransactionCommandHandlerDecorator<>),
typeof(ICommandHandler<>),
fromKey: "commandHandler");
var container = builder.Build();
var commandHandler = container.Resolve<ICommandHandler<MoveCustomerCommand>>();
commandHandler.Handle(new MoveCustomerCommand());
将输出:
TransactionCommandHandlerDecorator - before
MoveCustomerCommandHandler
TransactionCommandHandlerDecorator - after
我如何用DeadlockRetryCommandHandlerDecorator
装饰TransactionCommandHandlerDecorator
,以生成以下输出
DeadlockRetryCommandHandlerDecorator- before
TransactionCommandHandlerDecorator - before
MoveCustomerCommandHandler
TransactionCommandHandlerDecorator - after
DeadlockRetryCommandHandlerDecorator- after
@nemesv已经回答了这个问题,但我只是想补充一点,你可以添加一些简单的辅助方法,让Autofac:中的许多通用装饰器布线不那么痛苦
private static void RegisterHandlers(
ContainerBuilder builder,
Type handlerType,
params Type[] decorators)
{
RegisterHandlers(builder, handlerType);
for (int i = 0; i < decorators.Length; i++)
{
RegisterGenericDecorator(
builder,
decorators[i],
handlerType,
i == 0 ? handlerType : decorators[i - 1],
i != decorators.Length - 1);
}
}
private static void RegisterHandlers(ContainerBuilder builder, Type handlerType)
{
builder.RegisterAssemblyTypes(Assembly.GetExecutingAssembly())
.As(t => t.GetInterfaces()
.Where(v => v.IsClosedTypeOf(handlerType))
.Select(v => new KeyedService(handlerType.Name, v)))
.InstancePerRequest();
}
private static void RegisterGenericDecorator(
ContainerBuilder builder,
Type decoratorType,
Type decoratedServiceType,
Type fromKeyType,
bool hasKey)
{
var result = builder.RegisterGenericDecorator(
decoratorType,
decoratedServiceType,
fromKeyType.Name);
if (hasKey)
{
result.Keyed(decoratorType.Name, decoratedServiceType);
}
}
如果你把这些方法粘贴到你配置Autofac的地方,那么你可以这样做:
RegisterHandlers(
builder,
typeof(ICommandHandler<>),
typeof(TransactionCommandHandlerDecorator<>),
typeof(ValidationCommandHandlerDecorator<>));
它将连接所有的命令处理程序,并按照给定的顺序添加装饰器。
您只需要将"TransactionCommandHandlerRecorded"ICommandHandler
注册为Keyed
服务,并在注册第二个DeadlockRetryCommandHandlerDecorator
:时使用该新密钥
builder.RegisterGenericDecorator(
typeof(TransactionCommandHandlerDecorator<>),
typeof(ICommandHandler<>),
fromKey: "commandHandler")
.Keyed("decorated", typeof(ICommandHandler<>));
builder.RegisterGenericDecorator(
typeof(DeadlockRetryCommandHandlerDecorator<>),
typeof(ICommandHandler<>),
fromKey: "decorated");
您将得到以下输出:
DeadlockRetryCommandHandlerDecorator - before
TransactionCommandHandlerDecorator - before
MoveCustomerCommandHandler
TransactionCommandHandlerDecorator - after
DeadlockRetryCommandHandlerDecorator - after