Question

我正在学习Angular 2，并且在尝试创建服务时遇到了此错误。我试着寻找解决方案，但我看不出自己的错误。

错误：

angular2-polyfills.js:1243 TypeError: Tweet is not a constructor

代码：

export class TweetService{
    getTweets(){
        return tweets;
    }
}

let tweets = new Tweet("URL", "Author 1", "Handle 1", true, 50);

class Tweet {
    image: string;
    author: string;
    handle: string;
    status: "Lorem ipsum dolor sit amet.";
    isLiked: boolean;
    favorites: number;

    constructor(img, aut, hndl, ilkd, fav){
        img = this.image;
        aut = this.author;
        hndl = this.handle;
        ilkd = this.isLiked;
        fav = this.favorites;        
    }
}

Answer 1

你的let语句在类声明之外浮动。这将有效（但在一个真实的应用程序中，你将根据一些http调用或其他东西设置你的推文）：

import {Injectable} from '@angular/core';

@Injectable()
export class TweetService{
    getTweets(){
        let tweets = new Tweet("URL", "Author 1", "Handle 1", true, 50);
        return tweets;
    }
}

class Tweet {
    image: string;
    author: string;
    handle: string;
    status: "Lorem ipsum dolor sit amet.";
    isLiked: boolean;
    favorites: number;

    constructor(img, aut, hndl, ilkd, fav){
        this.image = img;
        this.author = aut;
        this.handle = hndl;
        this.isLiked = ilkd;
        this.favorites = fav;        
    }
}

Angular 2 / Typescript - TypeError：ClassName不是构造函数

1 个答案: