带有angularfire2的无限滚动

Question

我尝试使用firebase后端重新创建这个无限滚动的简单示例：https://angularfirebase.com/lessons/infinite-scroll-with-firebase-data-and-angular-animation/

问题是我想使用最新版本的angularfire2，而我却无法弄清楚如何重写1方法。

我坚持使用movies-list.components.ts文件的getMovies（）方法，因为在最新版本的angularfire2中没有＆＃39; do（）＆＃ 39; AngularFireList对象的方法。有没有办法在.take（1）.subscribe（）？

之前运行任意代码

private getMovies(key?) {
    if (this.finished) return

    this.movieService
        .getMovies(this.batch+1, this.lastKey)
        .do(movies => {

          /// set the lastKey in preparation for next query
          this.lastKey = _.last(movies)['$key']
          const newMovies = _.slice(movies, 0, this.batch)

          /// Get current movies in BehaviorSubject
          const currentMovies = this.movies.getValue()

          /// If data is identical, stop making queries
          if (this.lastKey == _.last(newMovies)['$key']) {
              this.finished = true
          }

          /// Concatenate new movies to current movies
          this.movies.next( _.concat(currentMovies, newMovies) )
        })
        .take(1)
        .subscribe()
}

Answer 1

do()在RxJS 6+中称为tap()。