7. 实现下拉刷新与上拉加载更多
其实跟以前一样，原生的ListView或者GridView都不能满足实际App的需要，很多时候都要通过自定义View去实现列表的下拉刷新和上拉加载，RecyclerView也是一样，不过这里不会介绍如何去自定义RecyclerView，相反，我们会借用SwipeRefreshLayout这个组件，更快地去实现列表刷新功能
界面布局如下：
<view
android:id="@+id/swipeRefreshLayout"
class="android.support.v4.widget.SwipeRefreshLayout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.RecyclerView
android:id="@+id/recyclerview"
android:layout_width="match_parent"
android:layout_height="match_parent">
</android.support.v7.widget.RecyclerView>
</view>
设置下拉刷新监听事件：
swipeRefreshLayout = (SwipeRefreshLayout) findViewById(R.id.swipeRefreshLayout);
swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
@Override
public void onRefresh() {
//重新获取数据
//获取完成swipeRefreshLayout.setRefreshing(false);
}
});
设置上拉加载更多可以通过设置滑动监听事件来实现：
recyclerview.setOnScrollListener(new RecyclerView.OnScrollListener() {
@Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
if (newState == RecyclerView.SCROLL_STATE_IDLE
&& lastVisibleItem + 1 == adapter.getItemCount()) {
swipeRefreshLayout.setRefreshing(true);
//分页获取数据
//获取完成swipeRefreshLayout.setRefreshing(false);
}
}
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
lastVisibleItem = mLayoutManager.findLastVisibleItemPosition();
}
});
