我正在尝试用新的 RecyclerView 替换我的 GridView(使用 GridLayoutManager),但它似乎不能很好地处理 gridLayoutAnimation(ClassCastException: LayoutAnimationController$AnimationParameters cannot be cast to GridLayoutAnimationController$AnimationParameters
)。它适用于常规布局动画,但由于它是网格,因此在平板电脑上需要很长时间才能完成。
我想要完成的类似于 Hierarchical Timing .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。常规布局动画会逐行执行动画,因此在较大的网格(例如平板电脑)上需要花费太多时间来完成。我也试过探索 ItemAnimator,但它只会像“不要”示例中那样同时在所有单元格上运行动画。
有没有办法在 RecyclerView 中完成这个网格布局动画?
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:基于 Galaxas0 的回答,here是一种只需要您使用扩展 RecyclerView
的自定义 View 的解决方案.基本上只覆盖 attachLayoutAnimationParameters()
方法。有了这个<gridLayoutAnimation>
与 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);
}
}
}
最佳答案
LayoutAnimationController
耦合到 ViewGroup
并且 ListView
和 GridView
都扩展了下面的方法以提供 child 的 动画参数
。问题是 GridLayoutAnimationController
需要它自己的不能类转换的 AnimationParameters
。
/**
* 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;
}
由于此方法默认添加一个 LayoutAnimationController.AnimationParameters
而不是 GridLayoutAnimationController.AnimationParameters
,因此解决方法应该是预先创建并附加一个。我们需要实现的是 GridView
已经做的事情:
@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
,我们能做的最接近的事情就是将修改塞进 onBindViewHolder()
中,这允许它们在 dispatchDraw
之前运行,触发动画的调用。
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,表明它是有效的。我硬编码的值也不适用于我的应用程序。
由于这是一个从 API 1 开始就存在的 API,没有真正的文档或示例,我强烈建议不要使用它,因为有很多方法可以复制它的功能。
关于android - 如何在 RecyclerView 中使用 GridLayoutAnimation?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/26539663/