实体类型"Task"需要定义主键

Question

我正在接受aspnetboilerplate.com关于使用他们的框架进行开发的教程的培训。我被困在第一个编码点，我必须创建一个基本的表"Task"，如下面的代码所述。

using System;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using Abp.Domain.Entities;
using Abp.Domain.Entities.Auditing;
using Abp.Timing; 
namespace WebApp.Tasks
{
[Table("AppTasks")]
public class Task : Entity, IHasCreationTime
{
public const int MaxTitleLength = 256;
public const int MaxDescriptionLength = 64 * 1024; //64KB
[Required]
[StringLength(MaxTitleLength)]
public string Title { get; set; }
[StringLength(MaxDescriptionLength)]
public string Description { get; set; }
public DateTime CreationTime { get; set; }
public TaskState State { get; set; }
public Task()
{
CreationTime = Clock.Now;
State = TaskState.Open;
}
public Task(string title, string description = null)
: this()
{
Title = title;
Description = description;
}
}
public enum TaskState: byte
{
Open = 0,
Completed = 1
}
}

我在WebAppDBContext中也添加了以下代码。

public class WebAppDbContext : AbpDbContext
{
public DbSet<Task> Tasks { get; set; } //<- This line
public WebAppDbContext(DbContextOptions<WebAppDbContext> options) 
: base(options)
{
}
}

教程没有提到关于这段代码的任何错误，但是每次我执行

命令时

Add-migration "Initial"

在包管理器控制台，我得到这个错误。

The entity type "Task" requires a primary key to be defined.

我在网上浏览了类似的错误，我发现的每个解决方案都不适合我…

更新#1:我编辑了代码，但错误仍然存在。

using System;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using Abp.Domain.Entities;
using Abp.Domain.Entities.Auditing;
using Abp.Timing;
namespace WebApp.Tasks
{
[Table("AppTasks")]
public class Task : Entity, IHasCreationTime
{
public const int MaxTitleLength = 256;
public const int MaxDescriptionLength = 64 * 1024; //64KB
[Key]
public int Id { get; set; }
[Required]
[StringLength(MaxTitleLength)]
public string Title { get; set; }
[StringLength(MaxDescriptionLength)]
public string Description { get; set; }
public DateTime CreationTime { get; set; }
public TaskState State { get; set; }
public Task()
{
CreationTime = Clock.Now;
State = TaskState.Open;
}
public Task(int id, string title, string description = null)
: this()
{
Id = id;
Title = title;
Description = description;
}
}
public enum TaskState: byte
{
Open = 0,
Completed = 1
}
}

教程链接:https://aspnetboilerplate.com/Pages/Documents/Articles/Introduction-With-AspNet-Core-And-Entity-Framework-Core-Part-1/index.html

更新#2:这是WebAppDbContext.cs

using Abp.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore;
using System.Threading.Tasks;
namespace WebApp.EntityFrameworkCore
{
public class WebAppDbContext : AbpDbContext
{
//Add DbSet properties for your entities...
public DbSet<Task> Tasks { get; set; }
public WebAppDbContext(DbContextOptions<WebAppDbContext> options) 
: base(options)
{
}
}
}

Answer 1

我试图复制你的代码在我的结束，我注意到，你正在处理的问题是由于错误的命名空间在上下文中WebAppDbContext。

using Abp.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore;
//using System.Threading.Tasks;//<------------ this line causes the error
using WebApp.Tasks; //<----------- You need to add this namespace.
namespace WebApp.EntityFrameworkCore
{
public class WebAppDbContext : AbpDbContext
{
//Add DbSet properties for your entities...
public DbSet<Task> Tasks { get; set; }
public WebAppDbContext(DbContextOptions<WebAppDbContext> options) 
: base(options)
{
}
}
}

问题是由于命名约定中的冲突造成的。我建议将实体的名称更改为其他名称，以防止将来发生进一步的冲突。