Android RecyclerView (四)總結（一）-（三）並且實現下拉重新整理資料，上拉載入資料功能
阿新 • • 發佈：2019-01-01
我們使用的程式碼還是為以前文章寫的。
這一次我們主要實現的是下拉重新整理資料，和上拉載入資料，這裡我都用Thread.sleep(xxx)的方法來模擬獲取資料等待。
首先我們下拉重新整理的時候要用到：
SwipeRefreshLayout
來看一下如何在佈局檔案中使用它:
...........
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<view
android:id="@+id/swipeRefreshLayout"
android:layout_width="match_parent"
class="android.support.v4.widget.SwipeRefreshLayout" 這裡可以看到我們給view設定了一個class就是android.support.v4.widget.SwipeRefreshLayout
這個元件，
接下來我們看一下程式碼部分
private SwipeRefreshLayout swipeRefreshLayout;
swipeRefreshLayout = (SwipeRefreshLayout) findViewById(R.id.swipeRefreshLayout);
swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
@Override
public void onRefresh() {
//重新獲取資料
//獲取完成swipeRefreshLayout.setRefreshing(false); 這裡是我們一個下拉重新整理的實現方法，
上拉載入資料。我們通過設定監聽器的方式來實現
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);
//分頁獲取資料
//獲取完成swipeRefreshLayout.setRefreshing(false);
}
}
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
lastVisibleItem = mLayoutManager.findLastVisibleItemPosition();
}
});當然我們肯定要用到執行緒和Handler處理。
下面我把整個從（一）到(四)的程式碼複製出來給大家看看。
這裡我用AS建立工程的時候選擇的是Basic Activity 這樣我們可以用它的
onOptionsItemSelected 來切換佈局.
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>
這裡主要就是一個.SwipeRefreshLayout裡面有一個RecyclerView控制元件
然後看一下 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 >這裡就是我們RecyclerView 的Item的一個佈局檔案。
接下來就是 menu檔案下的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="刪除"
app:showAsAction="never"
></item>
</menu>這裡就是為我們的PopMenu設定了一個Item選項，用於長按彈出刪除選單欄。
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();
}
}
這個就是RecyclerView的介面卡，這裡面我們寫出了他的設定監聽器方法，並且也有我們寫好的刪除Item的函式。
接下來就是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, "點選"+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(), "關閉PopupMenu", Toast.LENGTH_SHORT).show();
}
});
popupMenu.show();
}
}這裡面的就是用了SwipeRefreshLayout來實現下拉重新整理，然後通過給RecyclerView新增setOnScrollListener來實現上拉載入。
並且我們寫了一個Menu，點選後出現選單切換manager來實現不同的佈局。並且public void showPopMenu(View view,final int pos)這個函式也實現了顯示出一個選單欄並且刪除Item的方法，然後在LongOnClickListener裡呼叫這個方法就可以了。
這個就是RecyclerView學習的整個過程，其中還有很多不足的地方，只是為了記錄一下自己的學習過程，希望大神多多提出意見，勿噴。謝謝。