滚动时动画RecyclerView [英] Animate RecyclerView when scrolling

问题描述

有没有什么办法，当我把它的滚动动画一个RecyclerView的要素是什么？

Is there any way to animate the elements of a RecyclerView when I scroll it?

我看了看 DefaultItemAnimator 和 RecyclerView.ItemAnimator ，但动画似乎只是叫若数据集已更改，请纠正我，如果我错了。

I took a look at DefaultItemAnimator and RecyclerView.ItemAnimator, but that animations seems to be only called if the dataset has changed, please correct me if I am wrong.

我对 RecyclerView.ItemAnimator.animateMove有点糊涂了（）时，它叫什么名字？我把一些断点成类，但他们没有停止我的应用程序。

I'm a little confused about RecyclerView.ItemAnimator.animateMove() when is it called? I put some breakpoints into that class but none of them stops my app.

但回到我的问题我怎么能动画RecyclerView？我想，一些元素有另一种不透明，依赖于一些自定义规则。

However back to my question how can I animate the RecyclerView? I want that some elements have another opacity, depended on some custom rules.

我做了一些更多的reaseach似乎动画此举正是我要找的。这种方法是从 dispatchLayout称为（）。下面是该方法的javadoc的：

I did some more reaseach it seems that animation move is exactly that what I'm looking for. That methods are called from dispatchLayout(). Here is the javadoc of that method:

各地layoutChildren（）处理动画所造成的布局更改包装。    动画的假设工作，有五种不同类型的项目    在打法：
   持久性：项目是可见的前后布局
   删除：项目是布局前可见的是由应用程序中删除
   增加：项目布局之前并不存在，并通过应用程序
添加    消失：在设置前/后的数据存在的项目，而是从改变    可见在布局的过程不可见（它们被移出    画面的其他变化的副作用）
   出现：在之前设定的数据存在项/后，而是从改变    非可见的布局的过程中可见的（它们被移动了上    画面的其他变化的副作用）
   总体方法计算出哪些项目存在前/布局后    推断五个以上国家对每个项目之一。然后，动画    都设置了相应的：
   持久性的观点移动（{@link ItemAnimator＃animateMove（ViewHolder，INT，INT，INT，INT）}）    移除的视图将被删除（{@link ItemAnimator＃animateRemove（ViewHolder）}）
   增加的视图中添加（{@link ItemAnimator＃animateAdd（ViewHolder）}）
   消失的意见移出屏幕
   出现意见移动屏幕上的

Wrapper around layoutChildren() that handles animating changes caused by layout. Animations work on the assumption that there are five different kinds of items in play:
PERSISTENT: items are visible before and after layout
REMOVED: items were visible before layout and were removed by the app
ADDED: items did not exist before layout and were added by the app
DISAPPEARING: items exist in the data set before/after, but changed from visible to non-visible in the process of layout (they were moved off screen as a side-effect of other changes)
APPEARING: items exist in the data set before/after, but changed from non-visible to visible in the process of layout (they were moved on screen as a side-effect of other changes)
The overall approach figures out what items exist before/after layout and infers one of the five above states for each of the items. Then the animations are set up accordingly:
PERSISTENT views are moved ({@link ItemAnimator#animateMove(ViewHolder, int, int, int, int)}) REMOVED views are removed ({@link ItemAnimator#animateRemove(ViewHolder)})
ADDED views are added ({@link ItemAnimator#animateAdd(ViewHolder)})
DISAPPEARING views are moved off screen
APPEARING views are moved on screen

到目前为止，我在寻找持久的，消失与出现，但方法是从来没有所谓，因为这条线在这里：

So far I'm looking for PERSISTENT, DISAPPEARING and APPEARING, but that methods are never called because of this line here:

boolean animateChangesSimple = mItemAnimator != null && mItemsAddedOrRemoved
            && !mItemsChanged;

mItemsAddedOrRemoved 只是一直false，所以没有一个回调都曾经达到了。不知道如何正确设置设置的标志？

mItemsAddedOrRemoved is simply always false so none of that callback are ever reached. Any idea how to set set flag correctly?

推荐答案

我结束了在使用 OnScrollListener 在自定义的动画动画它（ ）方法。在我的情况是code仅需2ms的，这样是没有问题的60fps的。

I ended in using an OnScrollListener and animating it in a custom animate() method. In my case that code takes just 2ms so that is no problem for the 60fps.

recyclerView.setOnScrollListener(new RecyclerView.OnScrollListener() {
    @Override
    public void onScrollStateChanged(int newState) {
        if(newState == RecyclerView.SCROLL_STATE_IDLE) {
            // special handler to avoid displaying half elements
            scrollToNext();
        }
        animate();
    }

    @Override
    public void onScrolled(int dx, int dy) {
        animate();
    }
});

这篇关于滚动时动画RecyclerView的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！