来自android开发者(创建列表和卡片):
RecyclerView小部件是一个更高级和灵活的版本 列表视图。
好吧,这听起来很酷,但当我看到这张示例图片时,我真的很困惑这两者之间的区别。
上面的图片可以通过ListView使用自定义适配器轻松创建。
那么,在什么情况下应该使用RecyclerView呢?
来自android开发者(创建列表和卡片):
RecyclerView小部件是一个更高级和灵活的版本 列表视图。
好吧,这听起来很酷,但当我看到这张示例图片时,我真的很困惑这两者之间的区别。
上面的图片可以通过ListView使用自定义适配器轻松创建。
那么,在什么情况下应该使用RecyclerView呢?
当前回答
RecyclerView被创建为一个ListView的改进,所以是的,你可以创建一个附加列表与ListView控件,但使用RecyclerView更容易,因为它:
在向上/向下滚动时重用单元格——这在ListView适配器中实现View Holder是可能的,但这是一个可选的事情,而在RecycleView中,这是默认的写适配器的方式。 解耦列表从它的容器-所以你可以很容易地把列表项在运行时在不同的容器(线性布局,gridLayout)通过设置LayoutManager。
例子:
mRecyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);
mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
//or
mRecyclerView.setLayoutManager(new GridLayoutManager(this, 2));
动画常用列表动作——动画被解耦并委托给ItemAnimator。
还有更多关于RecyclerView的内容,但我认为这些要点是主要的。
因此,综上所述,RecyclerView是处理“列表数据”的一个更灵活的控件,它遵循关注点的委托模式,只留给自己一个任务——回收项目。
其他回答
除了以上差异之外,还有以下几个:
RV separates view creation and binding of data to view. In LV, you need to check if convertView is null or not for creating view, before binding data to it. So, in case of RV, view will be created only when it is needed but in case of LV, one can miss the check for convertview and will create view everytime. Switching between Grid and List is more easy now with LayoutManager. No need to notify and update all items, even if only single item is changed. One had to implement view caching in case of LV. It is provided in RV by default. (There is difference between view caching n recycling.) Very easy item animations in case of RV.
RecyclerView是一个新的ViewGroup,准备渲染任何 以类似的方式创建基于适配器的视图。它应该是 ListView和GridView的继承者,它可以在 最新的support-v7版本。已经开发了RecyclerView 考虑到可扩展性,因此可以创建任何类型的 你能想到的布局,但也不能没有一点恼人的地方 剂量。
安东尼奥·莱瓦的回答
compile 'com.android.support:recyclerview-v7:27.0.0'
RecyclerView确实是一个比ListView强大的视图。 欲了解更多详情,请访问此页面。
ListView是RecyclerView的祖先。有很多事情ListView没有做,或者做得不好。如果您要收集ListView的缺点,并通过将问题抽象到不同的域来解决问题,那么您最终会得到类似于回收器视图的东西。下面是ListViews的主要问题点:
Didn't enforce View Reuse for same item types (look at one of the adapters that are used in a ListView, if you study the getView method you will see that nothing prevents a programmer from creating a new view for every row even if one is passed in via the convertView variable) Didn't prevent costly findViewById uses(Even if you were recycling views as noted above it was possible for devs to be calling findViewById to update the displayed contents of child views. The main purpose of the ViewHolder pattern in ListViews was to cache the findViewById calls. However this was only available if you knew about it as it wasn't part of the platform at all) Only supported Vertical Scrolling with Row displayed Views (Recycler view doesn't care about where views are placed and how they are moved, it's abstracted into a LayoutManager. A Recycler can therefore support the traditional ListView as shown above, as well as things like the GridView, but it isn't limited to that, it can do more, but you have to do the programming foot work to make it happen). Animations to added/removed was not a use case that was considered. It was completely up to you to figure out how go about this (compare the RecyclerView. Adapter classes notify* method offerings v. ListViews to get an idea).
简而言之,RecyclerView是一个更灵活的ListView,尽管你可能需要做更多的编码工作。
In my opinion RecyclerView was made to address the problem with the recycle pattern used in listviews because it was making developer's life more difficult. All the other you could handle more or less. For instance I use the same adapter for ListView and GridView it doesn't matter in both views the getView, getItemCount, getTypeCount is used so it's the same. RecyclerView isn't needed if ListView with ListAdapter or GridView with grid adapters is already working for you. If you have implemented correctly the ViewHolder pattern in your listviews then you won't see any big improvement over RecycleView.
我只是想强调RecyclerView是兼容包的一部分。这意味着每个应用程序都有自己的RecyclerView实现,而不是使用来自操作系统的特性和代码。潜在地,类似RecyclerView的功能可以成为未来操作系统的一部分,从那里使用它是有益的。例如,Harmony OS很快就会发布。将来可以更改兼容性包许可证,这可能是一种暗示。缺点总结:
许可 更大的足迹,尤其是作为许多应用程序的一部分 如果一些来自操作系统的功能可以存在,那么效率就会下降
但值得注意的是,一些功能的实现,如滑动项目,来自RecyclerView。
以上所说的一切都必须加以考虑。