image.png
image.png
image.png
activity_main.xml
<android.support.v4.widget.SwipeRefreshLayout
android:id="@+id/sr_refresh"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.RecyclerView
android:id="@+id/rv_home"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</android.support.v4.widget.SwipeRefreshLayout>
item的布局 item_rv.xml 只有一个简单的TextView
item底部item_foot.xml
<ImageView
android:id="@+id/iv_foot"
android:layout_width="50dp"
android:layout_height="50dp"
android:background="@drawable/icon"/>
<TextView
android:id="@+id/tv_foot"
android:layout_toRightOf="@id/iv_foot"
android:layout_width="match_parent"
android:layout_height="50dp"
android:gravity="center"/>
看下Activity，下拉刷新主要是通过 SwipeRefreshLayout嵌套RecyclerView，实现OnRefreshListener方法，再重新设置数据给Recyclerview达到刷新数据的目的,这里我通过模拟数据达到刷新的效果，注释都有写。上拉加载更多则是通过监听Recyclerview的滑动（OnScrollListener），当其滑动到底部时对其原有数据进行增加达到加载更多数据的目的。
private RecyclerView recyclerView;
private SwipeRefreshLayout swipeRefreshLayout;
private List<String> mList;
private RecyclerAdapter adapter;
private int reTimes = 0;//更新次数
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
getData();
initRecyclerView();
}
private void initView() {
recyclerView = findViewById(R.id.rv_home);
swipeRefreshLayout = findViewById(R.id.sr_refresh);
swipeRefreshLayout.setOnRefreshListener(this);
mList = new ArrayList<>();
}
/**
* 初始化RecyclerView
*/
private void initRecyclerView() {
adapter = new RecyclerAdapter(mList, this);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
recyclerView.setItemAnimator(new DefaultItemAnimator());
recyclerView.setAdapter(adapter);
recyclerView.setOnScrollListener(new RecyclerView.OnScrollListener() {
@Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
//滑动到底部
if (newState == RecyclerView.SCROLL_STATE_IDLE) {
//recyclerview滑动到底部,更新数据
//加载更多数据
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
if (reTimes < 2) {
getMoreData();
//告诉他有更多数据
adapter.hasMore(true);
adapter.notifyDataSetChanged();
} else {
//没有数据了
adapter.hasMore(false);
adapter.notifyDataSetChanged();
}
}
}, 3000);
}
else {//滑上去了
adapter.hasMore(true);
// adapter.notifyDataSetChanged();
}
}
});
}
//刷新事件
@Override
public void onRefresh() {
//显示刷新动画效果
swipeRefreshLayout.setRefreshing(true);
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
//清空数据
adapter.reData();
//重新获取数据
getData();
//更新的数据
upData();
//重新设置有更多数据
adapter.hasMore(true);
reTimes = 0;
adapter.notifyDataSetChanged();
//隐藏刷新效果
swipeRefreshLayout.setRefreshing(false);
}
}, 3000);
}
//获取数据
public void getData() {
for (int i = 0; i < 20; i++) {
mList.add(i + "");
}
}
//加载更多数据
public void getMoreData() {
reTimes++;
List<String> moreList = new ArrayList<>();
for (int i = 0; i < 10; i++) {
moreList.add("加载的数据" + i);
}
mList.addAll(moreList);
}
//更新数据
private void upData() {
for (int i = 0; i < 5; i++) {
mList.add(0, "更新的数据" + i);
}
}
设配器,Recyclerview的item有2种，一种是正常的Item，另一种则是底部加载更多的Item（Foot），我们通过getItemViewType来判断返回的是哪种Item。
private List<String> mDatas;//数据
private int TYPE_ITEM = 0;//正常的Item
private int TYPE_FOOT = 1;//尾部刷新
private Context mContext;
private boolean hasMore = true;
public RecyclerAdapter(List<String> mDatas, Context mContext) {
this.mDatas = mDatas;
this.mContext = mContext;
}
//返回不同布局
@Override
public int getItemViewType(int position) {
if (position == getItemCount() - 1) {
return TYPE_FOOT;
}
return TYPE_ITEM;
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
if (viewType == TYPE_ITEM) {
return new ItemHolder(LayoutInflater.from(mContext).inflate(R.layout.item_rv, parent, false));
} else {
return new FootHolder(LayoutInflater.from(mContext).inflate(R.layout.item_foot, parent, false));
}
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
if (holder instanceof ItemHolder) {
((ItemHolder) holder).tv_item.setText("测试" + mDatas.get(position));
} else {
if (hasMore){
((FootHolder) holder).tv_foot.setText("正在加载更多。。");
((FootHolder) holder).iv_foot.setVisibility(View.VISIBLE);
}else {
((FootHolder) holder).tv_foot.setText("没有更多数据。。");
((FootHolder) holder).iv_foot.setVisibility(View.GONE);
}
}
}
//多出尾部刷新的item
@Override
public int getItemCount() {
return mDatas.size() + 1;
}
//item的holder
class ItemHolder extends RecyclerView.ViewHolder {
private TextView tv_item;
public ItemHolder(View itemView) {
super(itemView);
tv_item = itemView.findViewById(R.id.tv_item);
}
}
class FootHolder extends RecyclerView.ViewHolder {
private TextView tv_foot;
private ImageView iv_foot;
public FootHolder(View itemView) {
super(itemView);
tv_foot = itemView.findViewById(R.id.tv_foot);
iv_foot = itemView.findViewById(R.id.iv_foot);
}
}
//是否有更多数据
public void hasMore(boolean hamore) {
this.hasMore = hamore;
}
//这里清空数据，避免下拉刷新后，还显示上拉加载的数据
public void reData(){
mDatas.clear();
}
网友评论