class MyLayoutManager extends LinearLayoutManager {
public MyLayoutManager(Context context) {
super(context, LinearLayoutManager.VERTICAL, false);
}
@Override public void smoothScrollToPosition(RecyclerView recyclerView,
final RecyclerView.State state, final int position) {
int fcvip = findFirstCompletelyVisibleItemPosition();
int lcvip = findLastCompletelyVisibleItemPosition();
if (position < fcvip || lcvip < position) {
// scrolling to invisible position
float fcviY = findViewByPosition(fcvip).getY();
float lcviY = findViewByPosition(lcvip).getY();
recyclerView.setOnScrollListener(new RecyclerView.OnScrollListener() {
int currentState = RecyclerView.SCROLL_STATE_IDLE;
@Override public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
if (currentState == RecyclerView.SCROLL_STATE_SETTLING
&& newState == RecyclerView.SCROLL_STATE_IDLE) {
// recursive scrolling
smoothScrollToPosition(recyclerView, state, position);
}
currentState = newState;
}
@Override public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
int fcvip = findFirstCompletelyVisibleItemPosition();
int lcvip = findLastCompletelyVisibleItemPosition();
if ((dy < 0 && fcvip == position) || (dy > 0 && lcvip == position)) {
// stop scrolling
recyclerView.setOnScrollListener(null);
}
}
});
if (position < fcvip) {
// scroll up
recyclerView.smoothScrollBy(0, (int) (fcviY - lcviY));
} else {
// scroll down
recyclerView.smoothScrollBy(0, (int) (lcviY - fcviY));
}
} else {
// scrolling to visible position
float fromY = findViewByPosition(fcvip).getY();
float targetY = findViewByPosition(position).getY();
recyclerView.smoothScrollBy(0, (int) (targetY - fromY));
}
}
}
そして
MyLayoutManager layoutManager = new MyLayoutManager(context);
recyclerView.setLayoutManager(layoutManager);
RecyclerView.Adapter adapter = new YourAdapter();
recyclerView.setAdapter(adapter);
recyclerView.smoothScrollToPosition(adapter.getItemCount() - 1);
上記のコードは機能しますが、スムーズでなく、クールでもありません。
scrollToPosition
アダプタを設定した直後に電話していますか?