AutoMapper 返回空和 null

Question

根据以下内容将 Dto 映射到模型 - 映射 = 一个完全空的模型！

两个对象中混合了可为空和不可为空的引用。

模特


    public class TheModel
    {
        public Guid? Id { get; set; }
        public Guid Type { get; set; }
        public string Title { get; set; } = null!
        public string Description { get; set; } = null!;
        public string? ItIsAnything { get; set; }
    
        public string Internal { get; set; } = null!; 
        public string? AnotherInternal { get; set; }
    }

Dto


    public class TheDto
    {
        public Guid? Id { get; set; }
        public Guid Type { get; set; }
        public string? Title { get; set; } //  is nullable in the dto
        public string Description { get; set; } = null!;
        public string? ItIsAnything { get; set; }
    }

映射和执行 - Dto 到模型


    CreateMap<TheDto, TheModel>()
       .ForMember(dest => dest.Id, opt => opt.MapFrom(dto => dto.Id ?? Guid.Empty))
    
    // attempt for non-nullable references in Model that are nullable in Dto
    
       .ForMember(dest => dest.Internal , opt => opt.NullSubstitute("")); 
    
    // execute
    var dto = new TheDto{
        Id = null,
        Type = Guid.NewGuid(),
        Title = null;
        Description = "any desc";
    }
    
    var model = _mapper.Map<TheModel>(dto);
    
    ///// model is all empty !

Answer 1

您的 works fine for me except NullSubstitute 内部设置。如果源值在成员链中的任何位置为 null，但您在源上没有 Internal，它将被替换。例如，您可以这样做：

.AfterMap((dto, model) => model.Internal ??= "NotNull");

P.S.

对于 Id NullSubstitute 有效 (.ForMember(dest => dest.Id, opt => opt.NullSubstitute(Guid.Empty)))

Answer 2

我意识到问题出在模型绑定而不是映射

AutoMapper 返回空和 null

AutoMapper returnning empty and null

c#

automapper

c#-8.0

nullable-reference-types