领域驱动设计软件核心复杂性应对之道-实例解析.pptx

Domain Driven Design 101;Agenda;Software is complicated;We solve complexity in software by distilling our problems;public bool CanBook(Cargo cargo, Voyage voyage) { if (!overbookingPolicy.IsAllowed(cargo, voyage)) return false; ? ... };Domain Model;Ubiquitous language;public interface IPayrollService { double GetHourlyRate(Employee employee); };public class Employee { void ApplyForLeave(DateTime start, DateTime end, ILeaveService leaves) { ... } } ;Domain Expert;Entities;Value Types;public class Employee : IEquatableEmployee { public bool Equals(Employee other) { return this.Id.Equals(other.Id); } };public class Colour { public int Red { get; private set; } public int Green { get; private set; } public int Blue { get; private set; } ? public Colour(int red, int green, int blue) { this.Red = red; this.Green = green; this.Blue = blue; } ? public Colour MixInTo(Colour other) { return new Colour( Math.Avg(this.Red, other.Red), Math.Avg(this.Green, other.Green), Math.Avg(this.Blue, other.Blue)); } };Aggregates;;Repositories;public interface IEmployeeRepository { Employee GetById(int id); void Add(Employee employee); void Remove(Employee employee); ? IEnumerableEmployee GetStaffWorkingInRegion(Region region); } ;Domain Services;public interface ITripService { float GetDrivingDistanceBetween(Location a, Location b); } ;Specifications;class GoldCustomerSpecification : ISpecificationCustomer { public bool IsSatisfiedBy(Customer candidate) { return candidate.TotalPurchases 1000.0m; } } ?;to construct objects;var spec = new PizzaSpecification() .BasedOn(new MargaritaPizzaSpecification()) .WithThickCrust() .WithSwirl(Sauces.Bbq) .WithExtraCheese(); ? var pizza = new PizzaFac