如何在构造函数 1 中访问 constructor2 对象的对象值

Question

基本上我正在创建一个视频流应用程序并尝试在我的页面中显示 Result 构造函数的名称对象值，但显然它什么也没显示而且我不知道我哪里出错了。

我在 getVideo() 函数中遇到错误

export class Result {
    constructor(public id: string, public name: string, public imageUrl: string) {}
}

import {Result} from './res.model';

export class Video {
    constructor(
        public categoryId: string,
        public category: string,
        public results: Result[]
        ) {}
}

video.service.ts

private _data = new BehaviorSubject<Video[]>(
    [
      new Video('1', 'Action',
      [
        new Result('10', 'abc0', 'https://cleantechnica.com/files/2017/10/rimac.jpg'),
        new Result('11', 'abc1', 'https://cleantechnica.com/files/2017/10/rimac.jpg'),
        new Result('12', 'abc2', 'https://cleantechnica.com/files/2017/10/rimac.jpg')
      ]),
      new Video('2', 'Drama',
      [
        new Result('20', 'abc3', 'https://cleantechnica.com/files/2017/10/rimac.jpg'),
        new Result('21', 'abc4', 'https://cleantechnica.com/files/2017/10/rimac.jpg'),
        new Result('22', 'abc5', 'https://cleantechnica.com/files/2017/10/rimac.jpg')
      ])
    ]);

   get data() {
    return this._data.asObservable();
  }

   getVideo(resultId: string) {
    this._data.subscribe(videos => {
        return this.videos.find(video => {
          return video.results.find(result => { result.id = resultId; });
        });
    });

}

这是我的detailspage.ts

items: Video;
private videoSub: Subscription;
ngOnInit() {
    this.route.paramMap.subscribe(paramMap => {
      if (!paramMap.has('results.id')) {
        return;
      }
     this.videoSub = this.videoService.getVideo(paramMap.get('results.id')).subscribe(video => {
        this.items = video;
      });
    });
  }

detailspage.html

<ion-card>
    <ion-card-content>
      {{items.name}} 
    </ion-card-content>
</ion-card>

getVideo() 使用 map()

getVideos(id: string) {
  return this.data.pipe(take(1), map(result => {
    return {...result.find(p => {
      return {...p.find(videoId => videoId.id === id )};
    })};
  }));
}

我正在尝试显示 'name' 对象值 abc0、abc1、abc2...

Answer 1

编辑：

您的代码中有错字：

getVideo(resultId: string) {
    this._data.subscribe(videos => {
        return this.videos.find(video => {
          return video.results.find(result => { result.id =      resultId; }); // you are using ‘=‘ instead of ‘==‘ here
    });
});

Answer 2

问题在这里

  getVideo(resultId: string) {
    this._data.subscribe(videos => {
        return this.videos.find(video => {
          return video.results.find(result => result.id === resultId);
        });
    });

你正在订阅，returns 什么也不会去，你应该使用地图运算符，而且你不需要查找结果你需要检查视频是否有任何具有相同 resultIdd 的结果所以使用一些函数而不是查找

 getVideo(resultId: string) {
          return  this._data.pipe(map(videos => {
                return this.videos.find(video => {
                  return video.results.some(result =>  result.id===resultId);
                });
            }));

Answer 3

我想答案差不多就在这里了

videos: Video[];

get data() {
  return this._data.asObservable();
}

getVideo(resultId: string) {
  this._data.subscribe(videos => {
    const _video = videos.filter(video => video.results.map(x => x.id).indexOf(resultId) !== -1);
    this.videos =  _video;
  });
  return this.videos;
}

// another way, the same file does not need to subscribe to this file variable
getVideo(resultId: string): Video[] {
   const _data = this._data.getValue();
   const _videos = videos.filter(video => video.results.map(x => x.id).indexOf(resultId) !== -1);
   return _videos;
}

代码可以工作。

如何在构造函数 1 中访问 constructor2 对象的对象值

How to access object value of constructor2 object in constructor 1

typescript

angular

ionic4

如何在构造函数 1 中访问 c​​onstructor2 对象的对象值

How to access object value of constructor2 object in constructor 1

typescript

angular

ionic4

如何在构造函数 1 中访问 constructor2 对象的对象值