ASP.NET Core 控制器路由属性继承和抽象控制器操作 - AmbigouslyActionException

Question

我正在开发 ASP.NET Core Webapi 项目。我想为每个控制器通用的所有方法（例如 CRUD 方法）实现某种基本/抽象通用控制器，并在所有其他控制器中继承此控制器。我在下面附上示例代码：

public abstract class BaseApiController : Controller 
{
    [HttpGet]
    [Route("")]
    public virtual IActionResult GetAll() 
    {
        ...
    }

    [HttpGet]
    [Route("{id}")]
    public virtual IActionResult GetById(int id)
    {
        ...
    }

    [HttpPost]
    [Route("")]
    public virtual IActionResult Insert(myModel model)
    {
        ...
    }
}


[Route("api/Student")]
public class StudentController : BaseApiController 
{
    // Inherited endpoints:
    // GetAll method is available on api/Student [GET]
    // GetById method is available on api/Student/{id} [GET]
    // Insert method is available on api/Student [POST]
    //
    // Additional endpoints:
    // ShowNotes is available on api/Student/{id}/ShowNotes [GET]
    [HttpGet]
    [Route("{id}/ShowNotes")]
    public virtual IActionResult ShowNotes(int id) 
    {
        ...
    }
}

[Route("api/Teacher")]
public class TeacherController : BaseApiController 
{
    // Inherited endpoints:
    // GetAll method is available on api/Teacher [GET]
    // GetById method is available on api/Teacher/{id} [GET]
    // Insert method is available on api/Teacher [POST]
    //
    // Additional endpoints:
    // ShowHours is available on api/Teacher/{id}/ShowHours [GET]
    [HttpGet]
    [Route("{id}/ShowHours")]
    public virtual IActionResult ShowHours(int id) 
    {
        ...
    }
}

我在 .NET Framework WebApi 中看到过这种解决方案，带有额外的自定义 RouteProvider，例如：

public class WebApiCustomDirectRouteProvider : DefaultDirectRouteProvider
{
    protected override IReadOnlyList<IDirectRouteFactory> GetActionRouteFactories(HttpActionDescriptor actionDescriptor)
    {
        return actionDescriptor.GetCustomAttributes<IDirectRouteFactory>(inherit: true);
    }
}

每次我尝试到达派生控制器中的端点时，我都会收到 AmbigouslyActionException：

Multiple actions matched. The following actions matched route data and had all constraints satisfied:
XXX.WebApi.Controllers.CommonAppData.TeacherController.GetById
XXX.WebApi.Controllers.CommonAppData.StudentController.GetById

是否可以在 .NET Core WebApi 中创建这样的 Base 控制器？我应该如何编写它来达到操作方法而不在派生控制器中显式声明它？我应该如何配置这种解决方案？Startup 类中还有其他配置吗？

Answer 1

由于这个主题是一个很好的主题，所以它值得并且我解释了我是如何做到的。您可以像这样创建一个通用控制器：

[Route("api/[controller]/[action]")]
[ApiController]
public class BaseController<TEntity> : Controller where TEntity : class, new()
{
    private readonly YourDbContext _db;
    
    public BaseController(YourDbContext db)
    {
        _db=db;
    }
    
    public virtual async Task<IActionResult> GetAll()
    {
        var data= await _db.Set<TEntity>().ToListAsync();
        return View(data);
    }
    
    public virtual IActionResult GetById(int id)
    {
        var data= await _db.Set<TEntity>().FindAsync(e=>e.Id == id);
        return View(data);
    }
    .....
    
}

然后你可以像这样使用它：

public class StudentController : BaseController<Student> 
{
}

当然，您可以使用可选参数更好地编写它，如下所示：

public virtual async Task<IActionResult> GetAll(Expression<Func<TEntity, bool>>? predicate = null)
{
    var data= await _db.Set<TEntity>().Where(predicate).ToListAsync();
    ....
}

或者甚至根据需要覆盖继承控制器中的每个操作，并向操作添加必要的参数

public override Task<IActionResult> Get(....

我希望喜欢它；）并且不要忘记投票。