实例介绍
仿抖音流的图片浏览app，可以不断下滑加载高兴图。预加载屏幕下方的图片。点击可看大图，可保存到本地。
| @BindContentView(R.layout.fragment_recycler) | |
| class UnsplashPhotosFragment : BaseFragment(), UnsplashPhotosItemFactory.UnsplashPhotosItemEventListener, OnLoadMoreListener, androidx.swiperefreshlayout.widget.SwipeRefreshLayout.OnRefreshListener { | |
| private var adapter: AssemblyRecyclerAdapter? = null | |
| private var pageIndex = 1 | |
| private var backgroundImageUri: String? = null | |
| override fun onViewCreated(view: View, savedInstanceState: Bundle?) { | |
| super.onViewCreated(view, savedInstanceState) | |
| recycler_recyclerFragment_content.layoutManager = androidx.recyclerview.widget.LinearLayoutManager(context) | |
| refresh_recyclerFragment.setOnRefreshListener(this) | |
| if (adapter != null) { | |
| recycler_recyclerFragment_content.adapter = adapter | |
| } else { | |
| refresh_recyclerFragment.post { onRefresh() } | |
| } | |
| } | |
| override fun onUserVisibleChanged(isVisibleToUser: Boolean) { | |
| if (isVisibleToUser) { | |
| changeBackground(backgroundImageUri) | |
| } | |
| } | |
| private fun changeBackground(imageUri: String?) { | |
| this.backgroundImageUri = imageUri | |
| backgroundImageUri?.let { EventBus.getDefault().post(ChangeMainPageBgEvent(it)) } | |
| } | |
| private fun loadData(pageIndex: Int) { | |
| this.pageIndex = pageIndex | |
| NetServices.unsplash().listPhotos(pageIndex).enqueue(LoadDataCallback(this, pageIndex)) | |
| } | |
| override fun onClickImage(position: Int, image: UnsplashImage, optionsKey: String) { | |
| val activity = activity ?: return | |
| var finalOptionsKey: String? = optionsKey | |
| // 含有这些信息时，说明这张图片不仅仅是缩小，而是会被改变，因此不能用作loading图了 | |
| if (finalOptionsKey!!.contains("Resize") | |
| || finalOptionsKey.contains("ImageProcessor") | |
| || finalOptionsKey.contains("thumbnailMode")) { | |
| finalOptionsKey = null | |
| } | |
| @Suppress("UNCHECKED_CAST") | |
| val images = adapter!!.dataList as List<UnsplashImage> | |
| val imageArrayList = ArrayList<Image>(images.size) | |
| images.mapTo(imageArrayList) { Image(it.urls!!.regular!!, it.urls!!.raw!!) } | |
| ImageDetailActivity.launch(activity, dataTransferHelper.put("urlList", imageArrayList), finalOptionsKey!!, position) | |
| } | |
| override fun onClickUser(position: Int, user: UnsplashImage.User) { | |
| val uri = Uri.parse(user.links!!.html) | |
| .buildUpon() | |
| .appendQueryParameter("utm_source", "SketchSample") | |
| .appendQueryParameter("utm_medium", "referral") | |
| .appendQueryParameter("utm_campaign", "api-credit") | |
| .build() | |
| val intent = Intent(Intent.ACTION_VIEW) | |
| intent.data = uri | |
| startActivity(intent) | |
| } | |
| override fun onRefresh() { | |
| if (adapter != null) { | |
| adapter!!.loadMoreFinished(false) | |
| } | |
| if (!refresh_recyclerFragment.isRefreshing) { | |
| refresh_recyclerFragment.isRefreshing = true | |
| } | |
| loadData(1) | |
| } | |
| override fun onLoadMore(adapter1: AssemblyAdapter) { | |
| loadData(pageIndex 1) | |
| } | |
| private class LoadDataCallback internal constructor(fragment: UnsplashPhotosFragment, private val pageIndex: Int) : Callback<List<UnsplashImage>> { | |
| private val reference: WeakReference<UnsplashPhotosFragment> = WeakReference(fragment) | |
| init { | |
| if (pageIndex == 1) { | |
| fragment.hint_recyclerFragment.hidden() | |
| } | |
| } | |
| override fun onResponse(call: Call<List<UnsplashImage>>, response: Response<List<UnsplashImage>>) { | |
| val fragment = reference.get() ?: return | |
| if (!fragment.isViewCreated) { | |
| return | |
| } | |
| if (pageIndex == 1) { | |
| create(fragment, response) | |
| } else { | |
| loadMore(fragment, response) | |
| } | |
| fragment.refresh_recyclerFragment.isRefreshing = false | |
| } | |
| override fun onFailure(call: Call<List<UnsplashImage>>, t: Throwable) { | |
| val fragment = reference.get() ?: return | |
| val activity = fragment.activity ?: return | |
| if (!fragment.isViewCreated) { | |
| return | |
| } | |
| if (pageIndex == 1) { | |
| fragment.hint_recyclerFragment.failed(t, View.OnClickListener { fragment.onRefresh() }) | |
| fragment.refresh_recyclerFragment.isRefreshing = false | |
| } else { | |
| fragment.adapter!!.loadMoreFailed() | |
| Toast.makeText(fragment.activity, HintView.getCauseByException(activity, t), Toast.LENGTH_LONG).show() | |
| } | |
| } | |
| private fun create(fragment: UnsplashPhotosFragment, response: Response<List<UnsplashImage>>) { | |
| val activity = fragment.activity ?: return | |
| val images = response.body() | |
| if (images == null || images.isEmpty()) { | |
| fragment.hint_recyclerFragment.empty("No photos") | |
| return | |
| } | |
| val adapter = AssemblyRecyclerAdapter(images) | |
| adapter.addItemFactory(UnsplashPhotosItemFactory(activity, fragment)) | |
| adapter.setMoreItem(LoadMoreItemFactory(fragment)) | |
| fragment.recycler_recyclerFragment_content.adapter = adapter | |
| fragment.adapter = adapter | |
| fragment.changeBackground(images[0].urls!!.thumb) | |
| } | |
| private fun loadMore(fragment: UnsplashPhotosFragment, response: Response<List<UnsplashImage>>) { | |
| val images = response.body() | |
| if (images == null || images.isEmpty()) { | |
| fragment.adapter!!.loadMoreFinished(true) | |
| return | |
| } | |
| fragment.adapter!!.addAll(images) | |
| fragment.adapter!!.loadMoreFinished(images.size < 20) | |
| fragment.changeBackground(images[0].urls!!.thumb) | |
| } | |
| } | |
| } |
好例子网口号：伸出你的我的手 — 分享！
小贴士
感谢您为本站写下的评论，您的评论对其它用户来说具有重要的参考价值，所以请认真填写。
- 类似“顶”、“沙发”之类没有营养的文字，对勤劳贡献的楼主来说是令人沮丧的反馈信息。
- 相信您也不想看到一排文字/表情墙，所以请不要反馈意义不大的重复字符，也请尽量不要纯表情的回复。
- 提问之前请再仔细看一遍楼主的说明，或许是您遗漏了。
- 请勿到处挖坑绊人、招贴广告。既占空间让人厌烦，又没人会搭理，于人于己都无利。
关于好例子网
本站旨在为广大IT学习爱好者提供一个非营利性互相学习交流分享平台。本站所有资源都可以被免费获取学习研究。本站资源来自网友分享，对搜索内容的合法性不具有预见性、识别性、控制性，仅供学习研究，请务必在下载后24小时内给予删除，不得用于其他任何用途，否则后果自负。基于互联网的特殊性，平台无法对用户传输的作品、信息、内容的权属或合法性、安全性、合规性、真实性、科学性、完整权、有效性等进行实质审查；无论平台是否已进行审查，用户均应自行承担因其传输的作品、信息、内容而可能或已经产生的侵权或权属纠纷等法律责任。本站所有资源不代表本站的观点或立场，基于网友分享，根据中国法律《信息网络传播权保护条例》第二十二与二十三条之规定，若资源存在侵权或相关问题请联系本站客服人员，点此联系我们。关于更多版权及免责申明参见 版权及免责申明
网友评论
我要评论