public class Task : Entity<long>
{
 [ForeignKey("AssignedPersonId")]
 public virtual Person AssignedPerson { get; set; }

 public virtual int? AssignedPersonId { get; set; }

 public virtual string Description { get; set; }

 public virtual DateTime CreationTime { get; set; }

 public virtual TaskState State { get; set; }

 public Task()
 {
 CreationTime = DateTime.Now;
 State = TaskState.Active;
 }
}

public class Person : Entity
{
 public virtual string Name { get; set; }
}

public class SimpleTaskSystemDbContext : AbpDbContext
{
 public virtual IDbSet<Task> Tasks { get; set; }

 public virtual IDbSet<Person> People { get; set; }

 public SimpleTaskSystemDbContext()
 : base("Default")
 {

 }

 public SimpleTaskSystemDbContext(string nameOrConnectionString)
 : base(nameOrConnectionString)
 {
 
 }
}

DbMigrationsConfiguration<SimpleTaskSystem.EntityFramework.SimpleTaskSystemDbContext>
{
 public Configuration()
 {
 AutomaticMigrationsEnabled = false;
 }

 protected override void Seed(SimpleTaskSystem.EntityFramework.SimpleTaskSystemDbContext context)
 {
 context.People.AddOrUpdate(
 p => p.Name,
 new Person {Name = "Isaac Asimov"},
 new Person {Name = "Thomas More"},
 new Person {Name = "George Orwell"},
 new Person {Name = "Douglas Adams"}
 );
 }
}

public partial class InitialCreate : DbMigration
{
 public override void Up()
 {
 CreateTable(
 "dbo.StsPeople",
 c => new
 {
 Id = c.Int(nullable: false, identity: true),
 Name = c.String(),
 })
 .PrimaryKey(t => t.Id);
 
 CreateTable(
 "dbo.StsTasks",
 c => new
 {
 Id = c.Long(nullable: false, identity: true),
 AssignedPersonId = c.Int(),
 Description = c.String(),
 CreationTime = c.DateTime(nullable: false),
 State = c.Byte(nullable: false),
 })
 .PrimaryKey(t => t.Id)
 .ForeignKey("dbo.StsPeople", t => t.AssignedPersonId)
 .Index(t => t.AssignedPersonId); 
 }
 
 public override void Down()
 {
 DropForeignKey("dbo.StsTasks", "AssignedPersonId", "dbo.StsPeople");
 DropIndex("dbo.StsTasks", new[] { "AssignedPersonId" });
 DropTable("dbo.StsTasks");
 DropTable("dbo.StsPeople");
 }
}

PM> Update-Database

public interface ITaskRepository : IRepository<Task, long>
{
 List<Task> GetAllWithPeople(int? assignedPersonId, TaskState? state);
}

public class TaskRepository : SimpleTaskSystemRepositoryBase<Task, long>, ITaskRepository
{
 public List<Task> GetAllWithPeople(int? assignedPersonId, TaskState? state)
 {
 //在倉儲方法中，不用處理數據庫連接、DbContext和數據事務，ABP框架會自動處理。
 
 var query = GetAll(); //GetAll() 返回一個 IQueryable<T>接口類型
 
 //添加一些Where條件

 if (assignedPersonId.HasValue)
 {
 query = query.Where(task => task.AssignedPerson.Id == assignedPersonId.Value);
 }

 if (state.HasValue)
 {
 query = query.Where(task => task.State == state);
 }

 return query
 .OrderByDescending(task => task.CreationTime)
 .Include(task => task.AssignedPerson)
 .ToList();
 }
}

public interface ITaskAppService : IApplicationService
{
 GetTasksOutput GetTasks(GetTasksInput input);
 void UpdateTask(UpdateTaskInput input);
 void CreateTask(CreateTaskInput input);
}

public class TaskAppService : ApplicationService, ITaskAppService
{
 private readonly ITaskRepository _taskRepository;
 private readonly IRepository<Person> _personRepository;
 
 /// <summary>
 /// 構造函數自動注入我們所需要的類或接口
 /// </summary>
 public TaskAppService(ITaskRepository taskRepository, IRepository<Person> personRepository)
 {
 _taskRepository = taskRepository;
 _personRepository = personRepository;
 }
 
 public GetTasksOutput GetTasks(GetTasksInput input)
 {
 //調用Task倉儲的特定方法GetAllWithPeople
 var tasks = _taskRepository.GetAllWithPeople(input.AssignedPersonId, input.State);

 //用AutoMapper自動將List<Task>轉換成List<TaskDto>
 return new GetTasksOutput
 {
 Tasks = Mapper.Map<List<TaskDto>>(tasks)
 };
 }
 
 public void UpdateTask(UpdateTaskInput input)
 {
 //可以直接Logger,它在ApplicationService基類中定義的
 Logger.Info("Updating a task for input: " + input);

 //通過倉儲基類的通用方法Get，獲取指定Id的Task實體對象
 var task = _taskRepository.Get(input.TaskId);

 //修改task實體的屬性值
 if (input.State.HasValue)
 {
 task.State = input.State.Value;
 }

 if (input.AssignedPersonId.HasValue)
 {
 task.AssignedPerson = _personRepository.Load(input.AssignedPersonId.Value);
 }

 //我們都不需要調用Update方法
 //因為應用服務層的方法默認開啟了工作單元模式（Unit of Work）
 //ABP框架會工作單元完成時自動保存對實體的所有更改，除非有異常拋出。有異常時會自動回滾，因為工作單元默認開啟數據庫事務。
 }

 public void CreateTask(CreateTaskInput input)
 {
 Logger.Info("Creating a task for input: " + input);

 //通過輸入參數，創建一個新的Task實體
 var task = new Task { Description = input.Description };

 if (input.AssignedPersonId.HasValue)
 {
 task.AssignedPersonId = input.AssignedPersonId.Value;
 }

 //調用倉儲基類的Insert方法把實體保存到數據庫中
 _taskRepository.Insert(task);
 }
}

public class CreateTaskInput : IInputDto
{
 public int? AssignedPersonId { get; set; }

 [Required]
 public string Description { get; set; }
}

public class UpdateTaskInput : IInputDto, ICustomValidate
{
 [Range(1, long.MaxValue)]
 public long TaskId { get; set; }

 public int? AssignedPersonId { get; set; }

 public TaskState? State { get; set; }

 public void AddValidationErrors(List<ValidationResult> results)
 {
 if (AssignedPersonId == null && State == null)
 {
 results.Add(new ValidationResult("AssignedPersonId和State不能同時為空!", new[] { "AssignedPersonId", "State" }));
 }
 }
}

DynamicApiControllerBuilder
 .ForAll<IApplicationService>(Assembly.GetAssembly(typeof (SimpleTaskSystemApplicationModule)), "tasksystem")
 .Build();