ASP.NET Core Web API 在 API GET 请求中检索空白记录

Question

我正在使用 ASP.NET Core Web API。我有这些模型：

public abstract class EntityBase
{
    [Key]
    public int Id { get; set; }
}

public class Mandate : EntityBase
{
    public int? MerchantId { get; set; }

    public DateTime DueDate { get; set; }
    public DateTime StartDate { get; set; }
    public DateTime EndDate { get; set; }

    [ForeignKey("MerchantId")]
    public virtual Merchant Merchant { get; set; }
}

模型：授权

视图模型（Dto）：

public class MandateGetDto
{
    public int? MerchantId { get; set; }
    public DateTime DueDate { get; set; }
    public DateTime StartDate { get; set; }
    public DateTime EndDate { get; set; }
}

IBaseRepository：

public interface IBaseRepository<T> where T : BaseEntity
{

    Task<IEnumerable<T>> GetAll();
    bool EntityExists(long id);
}

基础存储库：

public class BaseRepository<T> : IBaseRepository<T> where T : AuditableBaseEntity
{
    private readonly DDMDbContext _context;
    private DbSet<T> _entities;

    public BaseRepository(DDMDbContext context)
    {
        _context = context;
        _entities = context.Set<T>();
    }

    public async Task<IEnumerable<T>> GetAll()
    {
        var list = await _entities.ToListAsync();
        return list;
    }
    public bool EntityExists(long id)
    {
        return _entities.Any(x => x.Id == id);
    }
}

实体映射器：

    public MandateGetDto FromMandateToMandateGetDto(Mandate mandate)
    {
        MandateGetDto mandateDto = new MandateGetDto();
        mandateDto.MerchantId = mandate.MerchantId;
        mandateDto.DueDate = mandate.DueDate;
        mandateDto.StartDate = mandate.StartDate;
        mandateDto.EndDate = mandate.EndDate;

        return mandateDto;
    }

工作单元：

public class UnitOfWork : IUnitOfWork
{
    private readonly DContext _context;

    public UnitOfWork(DContext context)
    {
        _context = context;
    }
    #region Mandate
    private readonly IBaseRepository<Mandate> _mandateRepository;

    public IBaseRepository<Mandate> MandateRepository => _mandateRepository ?? new BaseRepository<Mandate>(_context);
    # endregion

    public void Dispose()
    {
        if (_context != null)
        {
            _context.Dispose();
        }
    }
}

下面是我为 Mandate 服务编写的代码，它检索所有的授权记录。

授权服务：

    public async Task<ResponsePagination<GenericPagination<MandateGetDto>>> GetAll(int page, int sizeByPage)
    {
        string nextRoute = null, previousRoute = null;
        IEnumerable<Mandate> data = await _unitOfWork.MandateRepository.GetAll();

        var mapper = new EntityMapper();
        var mandatesDto = data.Select(m => mapper.FromMandateToMandateGetDto(m)).ToList();

        GenericPagination<MandateGetDto> objGenericPagination = GenericPagination<MandateGetDto>.Create(mandatesDto, page, sizeByPage);
        ResponsePagination<GenericPagination<MandateGetDto>> response = new ResponsePagination<GenericPagination<MandateGetDto>>(objGenericPagination);
        response.CurrentPage = objGenericPagination.CurrentPage;
        response.HasNextPage = objGenericPagination.HasNextPage;
        response.HasPreviousPage = objGenericPagination.HasPreviousPage;
        response.PageSize = objGenericPagination.PageSize;
        response.TotalPages = objGenericPagination.TotalPages;
        response.TotalRecords = objGenericPagination.TotalRecords;
        response.Data = objGenericPagination;

        if (response.HasNextPage)
        {
            nextRoute = $"/mandates?page={(page + 1)}";
            response.NextPageUrl = _uriPaginationService.GetPaginationUri(page, nextRoute).ToString();
        }
        else
        {
            response.NextPageUrl = null;
        }

        if (response.HasPreviousPage)
        {
            previousRoute = $"/mandates?page={(page - 1)}";
            response.PreviousPageUrl = _uriPaginationService.GetPaginationUri(page, previousRoute).ToString();
        }
        else
        {
            response.PreviousPageUrl = null;
        }
        return response;
    }

    public async Task<IEnumerable<Mandate>> GetMandates()
    {
        return await _unitOfWork.MandateRepository.GetAll();
    }

startup.cs：

services.AddTransient<IMandateService, MandateService>();

控制器：

[Produces("application/json")]
[ApiController]
[ApiVersion("1.0")]
public class AdminController : ControllerBase
{
    private readonly IMerchantService _merchantService;
    private readonly DDMDbContext _context;

    public AdminController(DDMDbContext context, IMerchantService merchantService)
    {
        _merchantService = merchantService;
        _context = context;
    }
    [HttpGet("mandates")]
    [Authorize]
    public async Task<ResponsePagination<GenericPagination<MandateGetDto>>> GetAllMyMandates(int page, int sizeByPage)
    {
        return await _mandateService.GetAll(page, sizeByPage);
    }

}

当我将 POSTMAN 用于获取请求时，我得到了以下响应：

{
    "current_page": 0,
    "page_size": 0,
    "total_pages": -2147483648,
    "total_records": 1,
    "has_next_page": false,
    "has_previous_page": false,
    "data": []
}

数据为空白，总记录为 1。

我该如何解决这个问题？

谢谢

Answer 1

您没有向我们展示您的代码的主要部分，即控制器

控制器 是您的 Web API 工作的原因。因此，如果您配置错误，它应该首先出现在控制器中，然后出现在其他地方。

向我们展示控制器的代码。

编辑

我不确定 DbSet 是否适合这种用法，但使用上下文对象对我有用。

你应该使用

_context.MandateOrWhateverElseItIs.ToListAsync();

而不是使用

_entities.ToListAsync();

使用 DbSet 可能是个问题，我建议使用上下文。我的应用程序在上下文中运行良好。

编辑

这是您在 BaseRepository 中的代码

public class BaseRepository<T> : IBaseRepository<T> where T : AuditableBaseEntity
{
    private readonly DDMDbContext _context;
    private DbSet<T> _entities;

    public BaseRepository(DDMDbContext context)
    {
        _context = context;
        _entities = context.Set<T>();
    }

    public async Task<IEnumerable<T>> GetAll()
    {
        var list = await _entities.ToListAsync();
        return list;
    }
    public bool EntityExists(long id)
    {
        return _entities.Any(x => x.Id == id);
    }
}

你应该把它改成什么

public class BaseRepository<T> : IBaseRepository<T> where T : AuditableBaseEntity
{
    private readonly DDMDbContext _context;
    private DbSet<T> _entities;

    public BaseRepository(DDMDbContext context)
    {
        _context = context;
        _entities = context.Set<T>();
    }

    public async Task<IEnumerable<T>> GetAll()
    {
        //Changes are here
        var list = await _context.EntitiesOrWhateverElseItIs.ToListAsync(); //I don't know what the option is, you can look it inside the autocomplete. Be sure to change EntitiesOrWhateverElseItIs with the option you see in autocomplete menu
        return list;
    }
    public bool EntityExists(long id)
    {
        return _entities.Any(x => x.Id == id);
    }
}