我在 Recycler View 下方有一个 fragment ，当向下滚动时， fragment 应该消失，当向上滚动时， fragment 应该重新出现
我实现了它，但问题是，当我向下滚动一点时，会出现 fragment 消失动画，当我进一步滚动时，它会重新出现并出现向下滑动动画，但我希望它保持隐藏状态，直到下一次向上滚动.
这是我的代码:
mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
@Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
Log.d("newstate",newState+"");
}
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
Log.d("dx",dx+"");
Log.d("dy",dy+"");
FragmentTransaction ft1 = getFragmentManager().beginTransaction();
ft1.setCustomAnimations(R.anim.entry, R.anim.exit);
ft1.show(bmfragment);
ft1.commit();
visibleItemCount = recyclerView.getChildCount();
totalItemCount = mLinearLayoutManager.getItemCount();
firstVisibleItem = mLinearLayoutManager.findFirstVisibleItemPosition();
if(dy<0) {
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.setCustomAnimations(R.anim.entry, R.anim.exit);
ft.show(bmfragment);
ft.commit();
}else if(firstVisibleItem>=1)
{
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.setCustomAnimations(0, R.anim.exit);
ft.hide(bmfragment);
ft.commit();
}
}
});
最佳答案
我明白了!我只是使用了一个标志变量
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
Log.d("dx",dx+"");
Log.d("dy",dy+"");
if(flag==false) {
FragmentTransaction ft1 = getFragmentManager().beginTransaction();
ft1.setCustomAnimations(R.anim.entry, R.anim.exit);
ft1.show(bmfragment);
ft1.commit();
visibleItemCount = recyclerView.getChildCount();
totalItemCount = mLinearLayoutManager.getItemCount();
firstVisibleItem = mLinearLayoutManager.findFirstVisibleItemPosition();
}
if(dy<0) {
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.setCustomAnimations(R.anim.entry, R.anim.exit);
ft.show(bmfragment);
ft.commit();
flag = false;
}else if(firstVisibleItem>=1)
{
if(flag==false) {
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.setCustomAnimations(0, R.anim.exit);
ft.hide(bmfragment);
ft.commit();
flag=true;
}
}
Log.d("visibleItemCount",visibleItemCount+"");
Log.d("firstVisibleItem",firstVisibleItem+"");
}
});
关于android - 滚动时只使用一次动画，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/38199465/