RxJava常用操作符 Observable.fromIterable

import io.reactivex.Observable

  val bannerItemData: ArrayList<HomeBean.Issue.Item> = mData.take(bannerItemSize).toCollection(ArrayList())
                val bannerFeedList = ArrayList<String>()
                val bannerTitleList = ArrayList<String>()
                //取出banner 顯示的 img 和 Title
                Observable.fromIterable(bannerItemData)
                        .subscribe { list ->
                            bannerFeedList.add(list.data?.cover?.feed ?: "")
                            bannerTitleList.add(list.data?.title ?: "")
                        }

                //設置 banner
                with(holder) {
                    getView<BGABanner>(R.id.banner).run {
                        setAutoPlayAble(bannerFeedList.size > 1)
                        setData(bannerFeedList, bannerTitleList)
                        setAdapter { banner, _, feedImageUrl, position ->
                            GlideApp.with(mContext)
                                    .load(feedImageUrl)
                                    .transition(DrawableTransitionOptions().crossFade())
                                    .placeholder(R.drawable.placeholder_banner)
                                    .into(banner.getItemImageView(position))


                        }

                    }
                }
                //沒有使用到的參數在 kotlin 中用"_"代替
                holder.getView<BGABanner>(R.id.banner).setDelegate { _, imageView, _, i ->

                    goToVideoPlayer(mContext as Activity, imageView, bannerItemData[i])

                }