c# - 使用 Automapper 创建记录时出错

Question

我正在使用 Visual Studio 2019、.NET Core 3.1。我正在尝试使用 Autoapper 创建一个 CRUD。在创建操作时出现错误，我尝试了几种形式，但似乎都没有。

错误：

The entity type 'CustomerCountriesDto' was not found. Ensure that the entity type has been added to the model.

在观点上：

@model ManufacturaMVC.Models.CustomerCountries

控制器：

private readonly ApplicationDbContext _context;
private readonly IMapper _mapper;
    
public CustomerCountriesController(ApplicationDbContext context, IMapper mapper)
{
    _context = context;
    _mapper = mapper;
}

public async Task<IActionResult> Create([Bind("CustomerCountries")] CustomerCountries customerCountries)
{
    if (ModelState.IsValid)
    {
        //var model = _mapper.Map<CustomerCountriesDto>(customerCountries);
        var user = _mapper.Map<CustomerCountries, CustomerCountriesDto>(customerCountries);
        _context.Add(user);
        await _context.SaveChangesAsync();                
        return RedirectToAction(nameof(Index));
    }
}

---

错误：

Missing type map configuration or unsupported mapping.

控制器：

public async Task<IActionResult> Create([Bind("CustomerCountriesDto")] CustomerCountries customerCountries)
{
    if (ModelState.IsValid)
    {
        var model = _mapper.Map<CustomerCountriesDto>(customerCountries);
        var user = _mapper.Map<CustomerCountriesDto, CustomerCountries>(customerCountries);
        _context.Add(user);
        await _context.SaveChangesAsync();                
        return RedirectToAction(nameof(Index));
    }
    return View(customerCountries);          
}

看法：

@model ManufacturaMVC.ViewModels.CustomerCountriesDto

---

错误：

The entity type 'CustomerCountriesDto' was not found

看法：

@model ManufacturaMVC.Models.CustomerCountries

控制器：

    public async Task<IActionResult> Create([Bind("CustomerCountriesDto")] CustomerCountries customerCountries)
{
    if (ModelState.IsValid)
    {
        var model = _mapper.Map<CustomerCountriesDto>(customerCountries);
        //var user = _mapper.Map<CustomerCountries, CustomerCountriesDto>(customerCountries);
        _context.Add(model);
        await _context.SaveChangesAsync();                
        return RedirectToAction(nameof(Index));
    }
    return View(customerCountries);          
}

---

楷模：

public class CustomerCountries
{
    [StringLength(50, ErrorMessage = "Longitud máxima para el país: 50")]
    public string CustomerCountry { get; set; }
    
    public ICollection<CustomerRegions> CustomerRegions { get; set; }
}

DTO：

public class CustomerCountriesDto
{
    public string CustomerCountry { get; set; }
}

映射配置文件：

public class AutoMapping : Profile
{
    public AutoMapping()
    {
        CreateMap<CustomerCountries, CustomerCountriesDto>(); 
    }
}

数据库上下文：

public class ApplicationDbContext : DbContext
{
    public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options)
        : base(options)
    {
    
    }
    
    public DbSet<Categories> Categories { get; set; }
    public DbSet<CustomerCities> CustomerCities { get; set; }
    public DbSet<CustomerCountries> CustomerCountries { get; set; }
    
    // More code ...

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Categories>().HasKey(m => m.CategoryId);
        modelBuilder.Entity<CustomerCities>().HasKey(m => m.CustomerCity);
        modelBuilder.Entity<CustomerCountries>().HasKey(m => m.CustomerCountry);
    }
}

有人可以告诉我正确的方法是什么，或者有什么问题吗？

标签： c#.net-corecontrollerautomapper

Answer 1

我认为你缺少 Dto 到类的映射，你有类到 Dto。

public class AutoMapping : Profile
{
    public AutoMapping()
    {
        CreateMap<CustomerCountries, CustomerCountriesDto>(); 
        //add this
        CreateMap<CustomerCountriesDto, CustomerCountries>();
    }
}

编辑：还发现您可以添加.ReverseMap()到映射中。那应该反过来覆盖映射。

public class AutoMapping : Profile
{
    public AutoMapping()
    {
        CreateMap<CustomerCountries, CustomerCountriesDto>().ReverseMap();       
    }
}