EntityFramework核心 - 更新记录失败，出现DbUpdateConcurrencyException

Question

我已经在这里阅读了有关该问题的其他问题，并且他们说他们忘了包含对象的ID。我在对象中有id：

但我仍然会收到错误：

  

Microsoft.EntityFrameworkCore.DbUpdateConcurrencyException：数据库   操作预计会影响1行，但实际上影响了0行。   自实体加载以来，数据可能已被修改或删除。

控制器：

[HttpPut("update")]
public async Task<IActionResult> Update([FromBody] ProgramModel model)
{
    var id = await _programService.UpdateAsync(model, _claimsService.GetSubIdFromClaims(User));

    if (id == 0)
    {
        return BadRequest();
    }

    return Created(string.Empty, new { id });
}

商务：

public async Task<int> UpdateAsync(ProgramModel model, string modifiedBy)
{
    _repository.Update(_mapper.Map<Program>(model), modifiedBy);
    return await _repository.SaveAsync();
}

Automapper：

public class ProgramProfile : Profile
{
    public ProgramProfile()
    {
        CreateMap<Program, ProgramModel>()
            .ReverseMap()
            .ForMember(dest => dest.Id, opts => opts.MapFrom(src => src.Id))
            .ForMember(dest => dest.Name, opts => opts.MapFrom(src => src.Name))
            .ForMember(dest => dest.Type, opts => opts.MapFrom(src => src.Type))
            .ForMember(dest => dest.Length, opts => opts.MapFrom(src => src.Length))
            .ForMember(dest => dest.TimesPerWeek, opts => opts.MapFrom(src => src.TimesPerWeek))
            .ForAllOtherMembers(m => m.Ignore());

        //CreateMap<ProgramModel, Program>();
    }
}

存储库：

实体值：

public virtual void Update<TEntity>(TEntity entity, string modifiedBy = null)
    where TEntity : class, IEntity
{
    entity.ModifiedDate = DateTime.UtcNow;
    entity.ModifiedBy = modifiedBy;
    context.Set<TEntity>().Attach(entity);
    context.Entry(entity).State = EntityState.Modified;
}

public virtual Task<int> SaveAsync()
{
    return context.SaveChangesAsync();
}

计划类：

public class Program : EntityMaximum
{
    public string Name { get; set; }
    public byte Type { get; set; }
    public int Length { get; set; }
    public byte TimesPerWeek { get; set; }
}

public class EntityMaximum : Entity<int>
{
    public bool IsActive { get; set; }
}

public abstract class Entity<T> : EntityMinimum, IEntity<T> 
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public T Id { get; set; }
    object IEntity.Id
    {
        get => Id;
        set => throw new NotImplementedException();
    }

    private DateTime? _createdDate;
    [DataType(DataType.DateTime)]
    public DateTime CreatedDate
    {
        get => _createdDate ?? DateTime.UtcNow;
        set => _createdDate = value;
    }


    [DataType(DataType.DateTime)]
    public DateTime? ModifiedDate { get; set; }

    public string ModifiedBy { get; set; }
}

public class EntityMinimum : IEntityMinimum
{
    public bool IsDeleted { get; set; }
    [Timestamp]
    public byte[] Version { get; set; }
    public string CreatedBy { get; set; }
}