[Architect] Abp 框架原理解析(5) UnitOfWork

本节目录

• 介绍
• 分析Abp源码
• 实现UOW

介绍

UOW(全称UnitOfWork)是指工作单元.

在Abp中,工作单元对于仓储和应用服务方法默认开启。并在一次请求中,共享同一个工作单元.

同时在Abp中,不仅支持同一个数据库连接,还支持事务处理.

分析Abp源码

1.UnitOfWorkRegistrar

2.ComponentRegistered

3.IsConventionalUowClass

4.Intercept

5.PerformSyncUow

实现UOW

定义IUnitOfWork

    public interface IUnitOfWork
    {
        //1.开启事务
        //2.设置Filter(本例中不做演示)
        void Begin(UnitOfWorkOptions options);

        void Complete();
    }
    public class UnitOfWorkOptions
    {
        public bool? IsTransactional { get; set; }
    }

实现uow,在uow中会提供db的创建,这样才能管理到每个db.

    public class EfUnitOfWork : UnitOfWorkBase
    {
        public static DbContext DbContext { get; set; }

        public static DbContext GetDbContext()
        {
            if (DbContext == null)
            {
                DbContext = new DemoDb();
            }
            return DbContext;
        }

        public override void Begin(UnitOfWorkOptions options)
        {
            if (options.IsTransactional == true)
            {
                CurrentTransaction = new TransactionScope();
            }
        }

        public TransactionScope CurrentTransaction { get; set; }

        public override void Complete()
        {
            SaveChanges();
            if (CurrentTransaction != null)
            {
                CurrentTransaction.Complete();
            }
        }

        private void SaveChanges()
        {
            DbContext.SaveChanges();
        }
    }
    public abstract class UnitOfWorkBase : IUnitOfWork
    {
        public virtual void Begin(UnitOfWorkOptions options)
        {
        }

        public virtual void Complete()
        {
        }
    }

定义与实现仓储层,这里不再做DbProvider.

    public interface IRepository
    {

    }

    public interface ITaskRepository : IRepository
    {
        void Add(Task task);
    }

    public class TaskRepository : ITaskRepository
    {
        public void Add(Task task)
        {
            var db = (DemoDb)EfUnitOfWork.GetDbContext();
            db.Tasks.Add(task);
        }
    }

定义与实现应用层

    public interface IApplicationService
    {

    }

    public interface ITaskAppService : IApplicationService
    {
        void CreateTask(CreateTaskInput input);
    }

    public class TaskAppService : ITaskAppService
    {
        private ITaskRepository _repository;
        public TaskAppService(ITaskRepository repository)
        {
            _repository = repository;
        }
        public void CreateTask(CreateTaskInput input)
        {
            _repository.Add(new Task(input.Name));
        }
    }

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

定义与实现uow拦截器

    internal class UnitOfWorkInterceptor : IInterceptor
    {
        private IUnitOfWork _unitOfWork;
        public UnitOfWorkInterceptor(IUnitOfWork unitOfWork)
        {
            _unitOfWork = unitOfWork;
        }
        public void Intercept(IInvocation invocation)
        {
            _unitOfWork.Begin(new UnitOfWorkOptions());
            invocation.Proceed();
            _unitOfWork.Complete();
        }
    }

定义在IApplicationService与IRepository接口下拦截

        static void Kernel_ComponentRegistered(string key, Castle.MicroKernel.IHandler handler)
        {
            var type = handler.ComponentModel.Implementation;
            if (typeof(IApplicationService).IsAssignableFrom(type) || typeof(IRepository).IsAssignableFrom(type))
            {
                handler.ComponentModel.Interceptors.Add(new InterceptorReference(typeof(UnitOfWorkInterceptor)));
            }
        }

执行

        static void Main(string[] args)
        {
            using (var container = new WindsorContainer())
            {
                container.Register(Component.For<IInterceptor, UnitOfWorkInterceptor>());//先注入拦截器
                container.Register(Component.For<IUnitOfWork, EfUnitOfWork>());
                container.Kernel.ComponentRegistered += Kernel_ComponentRegistered;
                container.Register(Component.For<ITaskAppService, TaskAppService>());
                container.Register(Component.For<ITaskRepository, TaskRepository>());
                var person = container.Resolve<ITaskAppService>();
                person.CreateTask(new CreateTaskInput() { Name = "3333" });
            }
            Console.ReadKey();
        }

会自动在application method的结尾调用Complete.

另外也可以在uow上定义option为启用事务.在本例中稍作扩展即可实现.

本文地址:http://neverc.cnblogs.com/p/5263558.html