android listview上拉刷新，新数据在前

实现 Android ListView 上拉刷新，并且让新数据在前面可以使用下拉刷新框架 SwipeRefreshLayout 和 RecyclerView。

1. 添加 SwipeRefreshLayout 和 RecyclerView

<androidx.swiperefreshlayout.widget.SwipeRefreshLayout
    android:id="@+id/swipe_refresh"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</androidx.swiperefreshlayout.widget.SwipeRefreshLayout>

2. 设置下拉刷新监听器

SwipeRefreshLayout swipeRefreshLayout = findViewById(R.id.swipe_refresh);
swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
    @Override
    public void onRefresh() {
        // 执行刷新操作
        // ...
    }
});

3. 设置 RecyclerView 布局管理器和适配器

RecyclerView recyclerView = findViewById(R.id.recycler_view);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
recyclerView.setAdapter(adapter);

4. 监听 RecyclerView 滚动事件，触发上拉加载更多

recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
    @Override
    public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
        super.onScrolled(recyclerView, dx, dy);
        LinearLayoutManager layoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
        if (layoutManager.findLastVisibleItemPosition() == adapter.getItemCount() - 1) {
            // 执行加载更多操作
            // ...
        }
    }
});

5. 将新数据插入到 RecyclerView 的顶部

adapter.addData(0, newData);

6. 结合下拉刷新和上拉加载更多实现完整的列表刷新

private void refreshData() {
    // 加载最新数据
    // ...
    swipeRefreshLayout.setRefreshing(false);
}

private void loadMoreData() {
    // 加载更多数据
    // ...
}

SwipeRefreshLayout swipeRefreshLayout = findViewById(R.id.swipe_refresh);
swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
    @Override
    public void onRefresh() {
        refreshData();
    }
});

RecyclerView recyclerView = findViewById(R.id.recycler_view);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
recyclerView.setAdapter(adapter);

recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
    @Override
    public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
        super.onScrolled(recyclerView, dx, dy);
        LinearLayoutManager layoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
        if (layoutManager.findLastVisibleItemPosition() == adapter.getItemCount() - 1) {
            loadMoreData();
        }
    }
});

这样做可以实现在 Android ListView 上拉刷新，并且让新数据在前面。