Android RecyclerView (四)总结（一）-（三）并且实现下拉刷新数据，上拉加载数据功能

我们使用的代码还是为以前文章写的。

这一次我们主要实现的是下拉刷新数据，和上拉加载数据，这里我都用Thread.sleep(xxx)的方法来模拟获取数据等待。

首先我们下拉刷新的时候要用到：

SwipeRefreshLayout

来看一下如何在布局文件中使用它:

...........
.....................
<view
android:id="@+id/swipeRefreshLayout"
android:layout_width="match_parent"
class="android.support.v4.widget.SwipeRefreshLayout"
android:layout_height="match_parent"
>
<android.support.v7.widget.RecyclerView
android:id="@+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent">
</android.support.v7.widget.RecyclerView>
</view>

这里可以看到我们给view设置了一个class就是android.support.v4.widget.SwipeRefreshLayout

这个组件，

接下来我们看一下代码部分

private SwipeRefreshLayout swipeRefreshLayout;
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);
}
});

这里是我们一个下拉刷新的实现方法，

上拉加载数据。我们通过设置监听器的方式来实现

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();
}
});

当然我们肯定要用到线程和Handler处理。

下面我把整个从（一）到(四)的代码复制出来给大家看看。

这里我用AS创建工程的时候选择的是Basic Activity 这样我们可以用它的

onOptionsItemSelected 来切换布局.

首先是 content_activity.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/content_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="com.example.administrator.leranrecycleerview2.MainActivity"
tools:showIn="@layout/activity_main">
<view
android:id="@+id/swipeRefreshLayout"
android:layout_width="match_parent"
class="android.support.v4.widget.SwipeRefreshLayout"
android:layout_height="match_parent"
>
<android.support.v7.widget.RecyclerView
android:id="@+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent">
</android.support.v7.widget.RecyclerView>
</view>
</RelativeLayout>

这里主要就是一个.SwipeRefreshLayout里面有一个RecyclerView控件

然后看一下 item_activity.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="72dp"
android:background="#ffdede"
android:layout_margin="3dp">
<TextView
android:id="@+id/textView"
android:layout_width="72dp"
android:layout_gravity="center"
android:layout_height="wrap_content"/>
</FrameLayout >

这里就是我们RecyclerView 的Item的一个布局文件。

接下来就是 menu文件下的item_menu.xml

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<item
android:id="@+id/removeItem"
android:title="删除"
app:showAsAction="never"
></item>
</menu>

这里就是为我们的PopMenu设置了一个Item选项，用于长按弹出删除菜单栏。

MyAdapter

public class MyAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private Context mContext;
private List<String> infos ;
private LayoutInflater inflater;
public interface OnItemOnClickLisener{
void onItemOnClickListener(View view ,int pos);
void onItemLongOnClickListener(View view,int pos);
}
private OnItemOnClickLisener onClickLisener;
public void setItemOnClickListener(OnItemOnClickLisener listener){
this.onClickLisener=listener;
}
public MyAdapter(Context mContext,List<String> infos){
this.mContext = mContext;
this.infos = infos;
}
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(this.mContext).inflate(R.layout.activity_item,parent,false);
ViewHolder viewHolder = new ViewHolder(view);
return viewHolder;
}

@Override
public void onBindViewHolder(final RecyclerView.ViewHolder holder, final int position) {
ViewHolder viewHolder = (ViewHolder) holder;
viewHolder.getTextView().setText(infos.get(position));
if(onClickLisener!=null){
holder.itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
int pos = holder.getLayoutPosition();
onClickLisener.onItemOnClickListener(holder.itemView,pos);
}
});
holder.itemView.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View view) {
int pos = holder.getLayoutPosition();
onClickLisener.onItemLongOnClickListener(holder.itemView,pos);
return false;
}
});
}
}
public void removeItem(int pos){
infos.remove(pos);
notifyItemRemoved(pos);
}
public void removeAll(){

notifyDataSetChanged();
}
class ViewHolder extends RecyclerView.ViewHolder{
private TextView textView;
public ViewHolder(View itemView) {
super(itemView);
textView  = (TextView) itemView.findViewById(R.id.textView);
}
public TextView getTextView(){
return textView;
}
}

public int getItemCount() {
return infos.size();
}
}

这个就是RecyclerView的适配器，这里面我们写出了他的设置监听器方法，并且也有我们写好的删除Item的函数。

接下来就是MainActivity

public class MainActivity extends AppCompatActivity {
private RecyclerView rcView;
private LinearLayoutManager manager;
private MyAdapter myAdapter;
private SwipeRefreshLayout swipeRefreshLayout;
private List<String> info;
Thread thread ;
Handler handler  = new Handler(){
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
if(msg.what==2){
info.clear();
refreshData();
myAdapter = new MyAdapter(MainActivity.this,info);
rcView.setAdapter(myAdapter);
swipeRefreshLayout.setRefreshing(false);
}else  if(msg.what==1){
for(int i=0;i<=10;i++)
info.add("123");
myAdapter = new MyAdapter(MainActivity.this,info);
rcView.setAdapter(myAdapter);
swipeRefreshLayout.setRefreshing(false);
}
}
};
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
rcView = (RecyclerView) findViewById(R.id.recycler_view);
manager = new LinearLayoutManager(this, LinearLayoutManager.VERTICAL,false);
info = new ArrayList<String>();
myAdapter = new MyAdapter(this,info);
loadData();
rcView.setLayoutManager(manager);
rcView.setAdapter(myAdapter);
rcView.setItemAnimator(new DefaultItemAnimator());
swipeRefreshLayout = (SwipeRefreshLayout) findViewById(R.id.swipeRefreshLayout);
swipeRefreshLayout.setColorSchemeResources(R.color.colorAccent,R.color.colorPrimary,R.color.cardview_dark_background,R.color.cardview_shadow_start_color);
swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {

@Override
public void onRefresh() {
new Thread(new Runnable() {
@Override
public void run() {
try {
Thread.sleep(2000);
handler.sendEmptyMessage(2);

} catch (InterruptedException e) {
e.printStackTrace();
}

}
}).start();

}
});
rcView.setOnScrollListener(new RecyclerView.OnScrollListener() {

int lastVisibleItem;
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
if(newState==RecyclerView.SCROLL_STATE_IDLE&&lastVisibleItem+1==myAdapter.getItemCount()){
swipeRefreshLayout.setRefreshing(true);
new Thread(new Runnable() {
@Override
public void run() {
try {
Thread.sleep(2000);
handler.sendEmptyMessage(1);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}).start();
}
}

@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
lastVisibleItem = manager.findLastVisibleItemPosition();
}
});
myAdapter.setItemOnClickListener(new MyAdapter.OnItemOnClickLisener() {
@Override
public void onItemOnClickListener(View view, int pos) {
Toast.makeText(MainActivity.this, "点击"+pos, Toast.LENGTH_SHORT).show();
}

@Override
public void onItemLongOnClickListener(View view, int pos) {
showPopMenu(view,pos);

}
});
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
}
public void loadData(){
for(int i=0;i<=15;i++){
info.add("Item:"+i);
}
}
public void refreshData(){
for(int i=0;i<=15;i++){
info.add("Item:");
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();

//noinspection SimplifiableIfStatement
switch (id){
case R.id.action_listView:
manager = new LinearLayoutManager(this,LinearLayoutManager.VERTICAL,false);
rcView.setLayoutManager(manager);
break;
case R.id.action_gridView:
rcView.setLayoutManager(new GridLayoutManager(this,3));
break;
case R.id.action_hr_gridView:
rcView.setLayoutManager(new StaggeredGridLayoutManager(6,StaggeredGridLayoutManager.HORIZONTAL));
break;
case R.id.action_straggerView:

break;

}

return super.onOptionsItemSelected(item);
}
public void showPopMenu(View view,final int pos){
PopupMenu popupMenu = new PopupMenu(this,view);
popupMenu.getMenuInflater().inflate(R.menu.item_menu,popupMenu.getMenu());
popupMenu.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
public boolean onMenuItemClick(MenuItem item) {

myAdapter.removeItem(pos);
return false;
}
});
popupMenu.setOnDismissListener(new PopupMenu.OnDismissListener() {
@Override
public void onDismiss(PopupMenu menu) {
Toast.makeText(getApplicationContext(), "关闭PopupMenu", Toast.LENGTH_SHORT).show();
}
});
popupMenu.show();
}
}

这里面的就是用了SwipeRefreshLayout来实现下拉刷新，然后通过给RecyclerView添加setOnScrollListener来实现上拉加载。

并且我们写了一个Menu，点击后出现菜单切换manager来实现不同的布局。并且public void showPopMenu(View view,final int pos)这个函数也实现了显示出一个菜单栏并且删除Item的方法，然后在LongOnClickListener里调用这个方法就可以了。

这个就是RecyclerView学习的整个过程，其中还有很多不足的地方，只是为了记录一下自己的学习过程，希望大神多多提出意见，勿喷。谢谢。