c# - 实体框架和 ASP.net MVC - 使用多对多关系更新实体模型

Question

使用 Asp.Net 身份和实体框架，我正在尝试更新 AspNetUser，并更改其 AspNetRole。

这是我的 UserDto 类：

public class UserDto : BaseDto
  {
        public string Uuid { get; set; }
        public string Email { get; set; }
        public string FullName { get; set; }
        public string UserName { get; set; }
        public List<RoleDto> Roles { get; set; }
        public int NumberOfLikes { get; set; }
        public int NumberOfComments { get; set; }
        public int NumberOfReviews { get; set; }
  }

这是我的 RoleDto 类：

public class RoleDto : BaseDto
    {
        [ScaffoldColumn(false)]
        public string Uuid { get; set; }

        [Required(ErrorMessage = "This field is required")]
        [MinLength(3, ErrorMessage = "Minimum 3 characters")]
        [DisplayName("Role Name")]
        public string Name { get; set; }

        [ScaffoldColumn(false)]
        public int NumberOfUsers { get; set; }
    }

这是我在 UserController 中的更新方法：

        [HttpPost]
        public ActionResult Edit(UserViewModel vm)
        {
            UserDto dto = new UserDto
            {
                Uuid = vm.Uuid,
                Email = vm.Email,
                FullName = vm.FullName,
                UserName = vm.UserName,
                Roles = new List<RoleDto>()
            };
            dto.Roles.Add(new RoleDto
            {
                Uuid = vm.RoleId
            });
            OpUserUpdate update = new OpUserUpdate();
            update.userDto = dto;

            var result = this.Manager.ExecuteOperation(update);

            return RedirectToAction("Index");
        }

这是用户更新操作：

    public class OpUserUpdate : OpUserBase
    {
        public override OperationResult Execute(FoodRestaurantEntities entities)
        {
            var id = this.userDto.Roles[0].Uuid;
            if (!string.IsNullOrWhiteSpace(this.userDto.Uuid))
            {
                var user = entities.AspNetUsers.FirstOrDefault(u => u.Id == this.userDto.Uuid);
                var role = entities.AspNetRoles.FirstOrDefault(r => r.Id == id);
                if(user != null)
                {
                    // If is set email
                    if (!string.IsNullOrWhiteSpace(this.userDto.Email))
                        user.Email = this.userDto.Email;

                    // If is set full name
                    if (!string.IsNullOrWhiteSpace(this.userDto.FullName))
                        user.FullName = this.userDto.FullName;

                    // If is set full name
                    if (!string.IsNullOrWhiteSpace(this.userDto.UserName))
                        user.UserName = this.userDto.UserName;

                    user.AspNetRoles.Add(role);
                    entities.SaveChanges();
                    this.Result.Status = true;
                    this.Result.Message = "Successfully updated";
                }
                else
                {
                    this.Result.Status = false;
                    this.Result.Message = "Not successfull";
                }

            }

            return Result;
        }
    }

1. OperationManager 类只执行操作 2. 问题是，user.AspNetRoles.Add(role)行只是为用户添加了另一个角色。例如，如果用户具有用户角色，它也会添加管理员角色，而不是将其更改为管理员。我究竟做错了什么？

标签： c#asp.net-mvcentity-framework