CodeGo.net>如何配置Autofac解析CQRS处理程序并在Web API项目中编写其查询调度程序

我在Project1的QUERY端有以下内容,主要包含接口

public interface IQueryResult {}
public interface IQuery<TResult> where TResult : IQueryResult {}
public interface IQueryHandler<TQuery, TResult> 
    where TQuery : IQuery<TResult> 
    where TResult : IQueryResult
{
    Task<TResult> HandleAsync(TQuery query);
}

public class PersonQueryResult : IQueryResult
{
    public string Name { get; set; }
}
public class GetPersonDetailsQuery : IQuery<PersonQueryResult>
{
    public int Id { get; set; }
}
public interface IQueryDispatcher
{
    Task<TResult> DispatchAsync<TQuery, TResult>(TQuery query)
        where TQuery : IQuery<TResult>
        where TResult : IQueryResult;
}

在引用项目1的第二个Project2中,我有

public class GetPersonDetailsQueryHandler : 
IQueryHandler<GetPersonDetailsQuery, PersonQueryResult>
{
    public Task<PersonQueryResult> HandleAsync(GetPersonDetailsQuery query)
    {
        return Task.FromResult( new PersonQueryResult {Name = "Bamboo"});
    }
}

最后一个项目3是一个Web API项目,该项目仅引用项目1而没有引用项目2.因此,它仅知道接口,命令和查询.我需要以一种可以轻松执行以下操作的方式配置autofac

var query = new GetPersonDetailsQuery { Id = 1 };
var magicHappensHere = new QueryDispatcher(); //any better way?
PersonQueryResult result = magicHappensHere.Dispatch(query); 

另外,我在Project 1中拥有的IQueryDispatcher似乎不适合上述工作.
该接口的示例实现可供参考.

public class QueryDispatcher : IQueryDispatcher
{
    private readonly IComponentContext _context;

    public QueryDispatcher(IComponentContext context)
    {
        this._context = context;
    }

    public Task<TResult> DispatchAsync<TQuery, TResult>(TQuery query) where TQuery : IQuery<TResult> where TResult : IQueryResult
    {
        var handler = _context.Resolve<IQueryHandler<TQuery, TResult>>();

        return handler.HandleAsync(query);
    }
}

我不知道如何实施的可能解决方案
(A)在Project 2中定义一个Autofac模块,然后在Web API中扫描Project 2程序集.
(B)http://docs.autofac.org/en/latest/register/registration.html#open-generic-components
(C)扫描装配并尝试自动映射.

在此插入代码需要帮助

private static void ConfigureAutofac(HttpConfiguration config) 
{
    var builder = new ContainerBuilder();
    //*************//
    //what to do here?
    //**************//
    builder.RegisterApiControllers(Assembly.GetExecutingAssembly());
    builder.RegisterWebApiFilterProvider(config);

    var container = builder.Build();
    config.DependencyResolver = new   AutofacWebApiDependencyResolver(container);
}    

解决方法:

最终得到了建议的解决方案(B)http://docs.autofac.org/en/latest/register/registration.html#open-generic-components.我也可以确认没有对dll的引用已添加到解决方案中

但是,我仍然需要一种很好的方法来从API项目中调度查询.更直观的东西

private static void ConfigureAutofac(HttpConfiguration config) 
{
    var builder = new ContainerBuilder();
    //*************//
    //heres what i did
    //*************//
    var assemblies = BuildManager.GetReferencedAssemblies().Cast<Assembly>();

    foreach (var assembly in assemblies)
    {
        builder.RegisterAssemblyTypes(assembly).AssignableTo<IQueryResult>().AsImplementedInterfaces();

        builder.RegisterAssemblyTypes(assembly).AsClosedTypesOf(typeof(IQuery<>)).AsImplementedInterfaces();

        builder.RegisterAssemblyTypes(assembly).AsClosedTypesOf(typeof(IQueryHandler<,>)).AsImplementedInterfaces();

    } 
    //rest of the code
}   

标签：dependency-injection,cqrs,c,inversion-of-control,autofac
来源： https://codeday.me/bug/20191118/2026785.html