Question

我有这两个代码片段如何更改它们，以便MemberModel可以作为泛型类型传递并保持不可实现，以便我可以将follow方法提取到自己的导出函数中？

export interface IFollowable {
    follow(user: IUserModel): IMemberModel;
}

export class CardModel implements ICardModel, IFollowable {
    public follow(user: IUserModel): IMemberModel {
        let member = new MemberModel({userId: user.id});
        member.role = UserRoles.follower;
        this.members.push(member);
        return member;
    }
}

如何制作follow和IFollowable泛型，以便我传入的任何类型都可以像MemberModel一样保持新的状态？

Answer 1

这样我传入的任何类型都可以保持新的状态，就像现在的MemberModel一样

因为在编译时擦除了typescript泛型，所以你需要明确地传递它们，例如使用如下所示的工厂：

type User = {name:string};
type Member = {name: string};
type MemberCreator = {new (user:User): Member};

interface Followable {
    follow(user: User, memberCreator: MemberCreator): Member;
}

export class CardModel implements Followable {
    public follow(user: User, memberCreator: MemberCreator): Member {
       return new memberCreator(user);
    }
}

如何使泛型类型约束成为可能

1 个答案: