我有一个使用LinearLayoutManager(垂直)的RecyclerView.我想要完成的是让项目装饰(全宽和1px高)分隔器动画与视图移动视图(translationY()正确处理)和视图更改其高度时.在我下面的当前代码中,分隔符将跳转到视图底部的未来位置,而不是动画期间的当前底部.有什么方法可以解释动画期间项目装饰的高度变化,使动画看起来更好吗？
我正在通过在RecyclerView的适配器上使用notifyItemChanged()来更改视图高度.
public class DividerItemDecoration extends RecyclerView.ItemDecoration {
private Drawable mDivider;
public DividerItemDecoration(Context context) {
mDivider = context.getResources().getDrawable(R.drawable.line_divider);
}
@Override
public void onDrawOver(Canvas c,RecyclerView parent,RecyclerView.State state) {
int right = parent.getWidth();
int dividerHeight = mDivider.getIntrinsicHeight();
int childCount = parent.getChildCount();
for (int i = 0; i < childCount - 1; i++) {
View child = parent.getChildAt(i);
View nextChild = parent.getChildAt(i + 1);
RecyclerView.LayoutParams layoutParams1 =
(RecyclerView.LayoutParams) child.getLayoutParams();
RecyclerView.LayoutParams layoutParams2 =
(RecyclerView.LayoutParams) nextChild.getLayoutParams();
int left = 0;
if (layoutParams1 != null && layoutParams2 != null) {
left = Math.min(layoutParams1.leftMargin,layoutParams2.leftMargin);
}
int ty = (int) (child.getTranslationY() + 0.5f);
int top = child.getBottom() + ty;
int bottom = top + dividerHeight;
mDivider.setBounds(
left,top,right,bottom);
mDivider.draw(c);
}
}
}
解决方法
我遇到过同样的问题.通过在onDraw方法中添加子项转换到计算来解决这个问题,如下所示：
@Override
public void onDraw(Canvas c,RecyclerView.State state) {
int left = parent.getPaddingLeft();
int right = parent.getWidth() - parent.getPaddingRight();
int childCount = parent.getChildCount();
for (int i = 0; i < childCount - 1; i++) {
View child = parent.getChildAt(i);
RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
//Here is the trick!
int top = child.getBottom() + params.bottomMargin + Math.round(child.getTranslationY());
int bottom = top + mDivider.getIntrinsicHeight();
mDivider.setBounds(left,bottom);
mDivider.draw(c);
}
}
