recyclerview悬浮条效果

最新推荐文章于 2023-06-26 18:42:37 发布

原创最新推荐文章于 2023-06-26 18:42:37 发布 · 243 阅读

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本文介绍了一个自定义RecyclerView滚动监听器，实现列表滚动时悬浮头部视图的效果。通过判断滚动方向及当前位置，更新悬浮头部的位置，确保在滚动过程中头部始终可见。

java代码：
private class SuspensionOnScrollListener extends RecyclerView.OnScrollListener {

    @Override
    public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
        super.onScrolled(recyclerView, dx, dy);
        LinearLayoutManager linearLayoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
        if (SuspensionBarAdapter.TYPETITLE == suspensionBarAdapter.getItemViewType(firstVisiblePoision + 1)) {
            LinearLayout nextView = (LinearLayout) linearLayoutManager.findViewByPosition(firstVisiblePoision + 1);
            if (nextView != null) {
                if (nextView.getTop() <= suspensionBarHeight) {
                    headContainer.setY(-(suspensionBarHeight - nextView.getTop()));
                }
            }
        }
        nextHeadPosition = getNextHeadPosition(dy > 0);
        if (firstVisiblePoision != linearLayoutManager.findFirstVisibleItemPosition()) {
            firstVisiblePoision = linearLayoutManager.findFirstVisibleItemPosition();
            headContainer.setY(0);
            updateHeadView(nextHeadPosition);
        }
    }
}

private int getNextHeadPosition(boolean isUp) {
    if (isUp) {
        if(SuspensionBarAdapter.TYPETITLE == suspensionBarAdapter.getItemViewType(firstVisiblePoision+1)){
            nextVisiblePosition = firstVisiblePoision+1;
        }
    } else {
        if (firstVisiblePoision > 0) {
            nextVisiblePosition = firstVisiblePoision - 1;
            while (SuspensionBarAdapter.TYPETITLE != suspensionBarAdapter.getItemViewType(nextVisiblePosition) && nextVisiblePosition > 0) {
                --nextVisiblePosition;
            }
        }
    }
    return nextVisiblePosition;
}



    布局
    <FrameLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/rv"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

    <include
        android:id="@+id/head_container"
        layout="@layout/title_item"/>
</FrameLayout>




使用：
recyclerView.addOnScrollListener(new SuspensionOnScrollListener());