在ASP.NET核心-6中，我试图为用户管理提取我所有的身份用户及其相关角色。

ApplicationUser

using Microsoft.AspNetCore.Identity;
namespace Core.Infrastructure.Identity
    public class ApplicationUser : IdentityUser
        public ICollection<ApplicationUserRole> UserRoles { get; set; }
}

ApplicationUserRole

using Microsoft.AspNetCore.Identity;
namespace Core.Infrastructure.Identity
    public class ApplicationUserRole : IdentityUserRole<string>
        public virtual ApplicationUser User { get; set; }
        public virtual ApplicationRole Role { get; set; }
}

ApplicationRole

using Microsoft.AspNetCore.Identity;
namespace Core.Infrastructure.Identity
    public class ApplicationRole : IdentityRole
        public ICollection<ApplicationUserRole> UserRoles { get; set; }
}

ApplicationUserConfigurations

using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Metadata.Builders;
namespace Core.Persistence.Configurations
    public class ApplicationUserConfigurations : IEntityTypeConfiguration<ApplicationUser>
        public void Configure(EntityTypeBuilder<ApplicationUser> builder)
            builder.Property(u => u.IsActive).HasDefaultValue(true);
            builder.Property(u => u.IsAdmin).HasDefaultValue(false);
            builder.Property(u => u.IsPasswordChanged).HasDefaultValue(false);
            builder.Property(u => u.IsDeleted).HasDefaultValue(false);
}

ApplicationRoleConfigurations

using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Metadata.Builders;
namespace Core.Persistence.Configurations
    public class ApplicationRoleConfigurations : IEntityTypeConfiguration<ApplicationRole>
        public void Configure(EntityTypeBuilder<ApplicationRole> builder)
            builder.HasIndex(r => r.Name).IsUnique();
            builder.Property(r => r.IsActive).HasDefaultValue(true);
}

ApplicationUserRoleConfigurations

using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Metadata.Builders;
public class ApplicationUserRoleConfigurations : IEntityTypeConfiguration<ApplicationUserRole<string>>
    public void Configure(EntityTypeBuilder<ApplicationUserRole<string>> builder)
        builder.HasKey(ur => new { ur.UserId, ur.RoleId });
        builder.HasOne(ur => ur.Role)
            .WithMany(r => r.UserRoles)
            .HasForeignKey(ur => ur.RoleId)
            .IsRequired();
        builder.HasOne(ur => ur.User)
            .WithMany(r => r.UserRoles)
            .HasForeignKey(ur => ur.UserId)
            .IsRequired();
}

DBContext

public class ApplicationDbContext
    : IdentityDbContext<ApplicationUser, ApplicationRole, string, IdentityUserClaim<string>,
    ApplicationUserRole, IdentityUserLogin<string>,
    IdentityRoleClaim<string>, IdentityUserToken<string>>
    public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options)
        : base(options)
        protected override void OnModelCreating(ModelBuilder builder)
            builder.ApplyConfigurationsFromAssembly(typeof(ApplicationDbContext).Assembly);
            base.OnModelCreating(builder);
            // Customize ASP.NET Identity models and override defaults
            // such as renaming ASP.NET Identity, changing key types etc.
            builder.ApplyConfiguration(new ApplicationUserConfigurations());
            builder.ApplyConfiguration(new ApplicationUserRoleConfigurations());
            builder.ApplyConfiguration(new IdentityRoleClaimConfigurations());
            builder.ApplyConfiguration(new IdentityUserClaimConfigurations());
            builder.ApplyConfiguration(new IdentityUserLoginConfigurations());
            builder.ApplyConfiguration(new IdentityUserClaimConfigurations());
            builder.ApplyConfiguration(new ApplicationRoleConfigurations());
}

我对 ApplicationUserRoleConfigurations 有意见

我发现了一个错误：

无法找到类型或命名空间名称‘

’(您是缺少使用指令还是程序集引用？)

然后，在 ApplicationUserRoleConfigurations 中突出显示

我怎么才能解决这个问题？

谢谢