Question

我试图用新的RecyclerView（使用GridLayoutManager）替换我的GridView，但似乎它不能很好地处理gridLayoutAnimation（ClassCastException: LayoutAnimationController$AnimationParameters cannot be cast to GridLayoutAnimationController$AnimationParameters）。它适用于常规布局动画，但因为它是一个网格，所以在平板电脑上完成它需要很长时间。

我想要完成的工作与Hierarchical Timing类似。如果您查看示例视频，它会显示布局动画从左上角到右下角。常规布局动画将逐行执行动画，因此在更大的网格（例如平板电脑）上花费太多时间来完成。我也曾尝试过探索ItemAnimator，但这只能在所有单元格上同时运行动画，就像在＆＃34; Don＆＃t;＆＃34;示例

有没有办法在RecyclerView中完成此网格布局动画？

这是gridview_layout_animation.xml：

<!-- replace gridLayoutAnimation with layoutAnimation and -->
<!-- replace column- and rowDelay with delay for RecyclerView -->

<gridLayoutAnimation xmlns:android="http://schemas.android.com/apk/res/android"
    android:columnDelay="15%"
    android:rowDelay="15%"
    android:animation="@anim/grow_in"
    android:animationOrder="normal"
    android:direction="top_to_bottom|left_to_right"
    android:interpolator="@android:interpolator/linear"
/>

这是动画grow_in.xml：

<set android:shareInterpolator="false"
 xmlns:android="http://schemas.android.com/apk/res/android">
    <scale
        android:interpolator="@android:interpolator/decelerate_quint"
        android:fromXScale="0.0"
        android:toXScale="1.0"
        android:fromYScale="0.0"
        android:toYScale="1.0"
        android:pivotX="50%"
        android:pivotY="50%"
        android:fillAfter="true"
        android:duration="400"
        android:startOffset="200"
    />
</set>

编辑：根据Galaxas0的回答，here是一种解决方案，只需要您使用扩展RecyclerView的自定义视图。基本上只覆盖attachLayoutAnimationParameters()方法。使用此<gridLayoutAnimation>可以像使用GridView一样工作。

public class GridRecyclerView extends RecyclerView {

    public GridRecyclerView(Context context) {
        super(context);
    }

    public GridRecyclerView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public GridRecyclerView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    @Override
    public void setLayoutManager(LayoutManager layout) {
        if (layout instanceof GridLayoutManager){
            super.setLayoutManager(layout);
        } else {
            throw new ClassCastException("You should only use a GridLayoutManager with GridRecyclerView.");
            }
        }

    @Override
    protected void attachLayoutAnimationParameters(View child, ViewGroup.LayoutParams params, int index, int count) {

        if (getAdapter() != null && getLayoutManager() instanceof GridLayoutManager){

            GridLayoutAnimationController.AnimationParameters animationParams =
                (GridLayoutAnimationController.AnimationParameters) params.layoutAnimationParameters;

            if (animationParams == null) {
                animationParams = new GridLayoutAnimationController.AnimationParameters();
                params.layoutAnimationParameters = animationParams;
            }

            int columns = ((GridLayoutManager) getLayoutManager()).getSpanCount();

            animationParams.count = count;
            animationParams.index = index;
            animationParams.columnsCount = columns;
            animationParams.rowsCount = count / columns;

            final int invertedIndex = count - 1 - index;
            animationParams.column = columns - 1 - (invertedIndex % columns);
            animationParams.row = animationParams.rowsCount - 1 - invertedIndex / columns;

        } else {
            super.attachLayoutAnimationParameters(child, params, index, count);
        }
    }
}

Answer 1

LayoutAnimationController与ViewGroup相关联，ListView和GridView都扩展了以下方法，以提供孩子animationParams。问题是GridLayoutAnimationController需要自己的AnimationParameters无法进行分类。

    /**
     * Subclasses should override this method to set layout animation
     * parameters on the supplied child.
     *
     * @param child the child to associate with animation parameters
     * @param params the child's layout parameters which hold the animation
     *        parameters
     * @param index the index of the child in the view group
     * @param count the number of children in the view group
     */
    protected void attachLayoutAnimationParameters(View child,
            LayoutParams params, int index, int count) {
        LayoutAnimationController.AnimationParameters animationParams =
                    params.layoutAnimationParameters;
        if (animationParams == null) {
            animationParams = new LayoutAnimationController.AnimationParameters();
            params.layoutAnimationParameters = animationParams;
        }

        animationParams.count = count;
        animationParams.index = index;
    }

由于默认情况下此方法会添加LayoutAnimationController.AnimationParameters而不是GridLayoutAnimationController.AnimationParameters，因此修复应该是事先创建并附加一个。我们需要实现的是GridView已经做了什么：

@Override
protected void attachLayoutAnimationParameters(View child,
        ViewGroup.LayoutParams params, int index, int count) {

    GridLayoutAnimationController.AnimationParameters animationParams =
            (GridLayoutAnimationController.AnimationParameters) params.layoutAnimationParameters;

    if (animationParams == null) {
        animationParams = new GridLayoutAnimationController.AnimationParameters();
        params.layoutAnimationParameters = animationParams;
    }

    animationParams.count = count;
    animationParams.index = index;
    animationParams.columnsCount = mNumColumns;
    animationParams.rowsCount = count / mNumColumns;

    if (!mStackFromBottom) {
        animationParams.column = index % mNumColumns;
        animationParams.row = index / mNumColumns;
    } else {
        final int invertedIndex = count - 1 - index;

        animationParams.column = mNumColumns - 1 - (invertedIndex % mNumColumns);
        animationParams.row = animationParams.rowsCount - 1 - invertedIndex / mNumColumns;
    }
}

要复制GridView，我们可以做的最接近的事情是将修改变为onBindViewHolder()，允许它们在触发动画的dispatchDraw之前运行。

ViewGroup.LayoutParams params = holder.itemView.getLayoutParams();
        GridLayoutAnimationController.AnimationParameters animationParams = new GridLayoutAnimationController.AnimationParameters();
        params.layoutAnimationParameters = animationParams;

        animationParams.count = 9;
        animationParams.columnsCount = 3;
        animationParams.rowsCount = 3;
        animationParams.index = position;
        animationParams.column = position / animationParams.columnsCount;
        animationParams.row = position % animationParams.columnsCount;

如果使用RecyclerView的新GridLayoutManager，请尝试从中获取参数。上面的示例是一个概念证明，表明它的工作原理。我的硬编码值也不适用于我的应用程序。

由于这是自API 1以来没有真正文档或样本的API，我强烈建议不要使用它，因为有很多方法可以复制其功能。

Answer 2

更简单的解决方案

TransitionManager.beginDelayedTransition(moviesGridRecycler);
gridLayoutManager.setSpanCount(gridColumns);
adapter.notifyDataSetChanged();

但不要忘记制作您的RecyclerAdapter setHasStableIds(true);并实施getItemID()

@Override
public long getItemId(int position) {
   return yourItemSpecificLongID;
}

Answer 3

在https://gist.github.com/Musenkishi/8df1ab549857756098ba

引用@Musenkishi

毫无头绪。设置适配器后是否正在调用recyclerView.scheduleLayoutAnimation();？您是否已将android:layoutAnimation="@anim/your_layout_animation"设置为布局中的<GridRecyclerView>？

这解决了我的问题。

如何在RecyclerView中使用GridLayoutAnimation？

3 个答案: