没有从ApplicationUser到IdentityUser的隐式引用转换

我正在尝试自定义一些ASP。. NET Identity使用泛型的核心类。

我的ApplicationUser类:

public class ApplicationUser : IdentityUser<Guid>//, ApplicationUserClaim, ApplicationRole, ApplicationUserLogin> 
{
    public ApplicationUser() {  }
}

我的ApplicationUserStore类:

public class ApplicationUserStore : UserStore<ApplicationUser, ApplicationRole, ApplicationDbContext, Guid> 
{
    public ApplicationUserStore(ApplicationDbContext ctx, IdentityErrorDescriber describer = null) : base(ctx, describer)
    {
    }
}

错误信息是:

AspDotNetCoreFullFramework.Identity。ApplicationUser 1[System.Guid]', on Microsoft.AspNetCore.Identity.EntityFrameworkCore.UserStore ' 8[TUser,TRole,TContext,TKey,TUserClaim,TUserRole,TUserLogin,TUserToken]'违反类型参数'TUser'的约束

现在，当我去到。net实现的UserStore(基类):

公共类UserStore<TUser,>：TUser, TRole, TContext, TKey，IdentityUserClaim<TKey&gt,>IdentityUserLogin<TKey&gt>在
where TUser: IdentityUser
… where TKey: equatable {

我可以看到ApplicationUser继承自IdentityUser。这个约束条件得到了满足。TKey是GUID，实现了equatableguid。此约束也满足。

那么问题是什么呢?

IdentityBuilder.AddEntityFrameworkStores<ApplicationDbContext,Guid>();