RecyclerView onScrollChangeListener

Question

当我向上和向下滚动RecyclerView时,我需要隐藏并显示一个浮动操作按钮,我已经在SDK 23下成功实现了这个,代码如下所示(newReminder是我需要隐藏和显示的按钮):

recyclerView.setOnScrollListener(new RecyclerView.OnScrollListener() {
@Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
    super.onScrollStateChanged(recyclerView, newState);
}

@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
    super.onScrolled(recyclerView, dx, dy);

    if (scrolledDistance > HIDE_THRESHOLD && !newReminder.isMenuButtonHidden()) {
        newReminder.hideMenuButton(true);
        scrolledDistance = 0;
    } else if (scrolledDistance < -HIDE_THRESHOLD && newReminder.isMenuButtonHidden()) {
        newReminder.showMenuButton(true);
        scrolledDistance = 0;
    }

    if((!newReminder.isMenuButtonHidden() && dy>0) || (newReminder.isMenuButtonHidden() && dy<0)) {
        scrolledDistance += dy;
    }
}

});

但是,对于SDK 23,当我使用onScrollChangeListener时,我对参数感到困惑,下面的代码不再起作用了:

if(Build.VERSION.SDK_INT > 22){
recyclerView.setOnScrollChangeListener(new View.OnScrollChangeListener() {
    @Override
    public void onScrollChange(View v, int scrollX, int scrollY, int oldScrollX, int oldScrollY) 
        if (scrolledDistance > HIDE_THRESHOLD && !newReminder.isMenuButtonHidden()) {
            newReminder.hideMenuButton(true);
        } else if (scrolledDistance < -HIDE_THRESHOLD && newReminder.isMenuButtonHidden()) {
            newReminder.showMenuButton(true);
        }
        if((!newReminder.isMenuButtonHidden() && scrollY > 0)
                || (newReminder.isMenuButtonHidden() && scrollY < 0)) {
            scrolledDistance = oldScrollY - scrollY;
        }
    }
});

}

我想我误解了scrollY和oldScrollY的含义,任何人都可以帮助我吗？谢谢!!!

Answer 1

setOnScrollChangeListener(OnScrollChangeListener l)是弃用方法的错误替换setOnScrollListener(OnScrollListener listener).

使用addOnScrollListener(OnScrollListener)和removeOnScrollListener(OnScrollListener)替代.这些方法与OnScrollListener参数相同,因此您不必担心逻辑中的更改.与以前的实现的唯一区别是,现在您可以向RecyclerView添加多个侦听器.

这是文档的链接