Android官方下拉刷新控件SwipeRefreshLayout使用详解


可能开发安卓的人大多数都用过很多下拉刷新的开源组件,但是今天用了官方v4支持包的SwipeRefreshLayout觉得效果也蛮不错的,特拿出来分享。

简介:
SwipeRefreshLayout组件只接受一个子组件:即需要刷新的那个组件。它使用一个侦听机制来通知拥有该组件的监听器有刷新事件发生,换句话说我们的Activity必须实现通知的接口。该Activity负责处理事件刷新和刷新相应的视图。一旦监听者接收到该事件,就决定了刷新过程中应处理的地方。如果要展示一个“刷新动画”,它必须调用setRefrshing(true),否则取消动画就调用setRefreshing(false)。 

并且这个东西只支持下拉刷新,大家可以自定义View继承它实现你的上拉加载。 

怎样使用SwipeRefreshLayout:

使用起来非常简单。

下面将用一个实例展示如何使用官方这个下拉刷新控件,末尾我还模仿虚拟实现了一个小的上拉加载效果,可以供大家向上分析。 

先上图: 

上点代码:

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
 xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 tools:context="com.example.nanchen.swiperefreshlayoutdemo.MainActivity">
 <android.support.v4.widget.SwipeRefreshLayout
  android:id="@+id/main_srl"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content">
  <ListView
   android:id="@+id/main_lv"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content">
  </ListView>
 </android.support.v4.widget.SwipeRefreshLayout>
</RelativeLayout>

menu_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
 <ProgressBar
  style="?android:attr/progressBarStyleSmall"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:id="@+id/progressBar"/>
 <TextView
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:text="正在玩命加载中...."
  android:id="@+id/textView2"/>
</LinearLayout>

MainActivity.java 

package com.example.nanchen.swiperefreshlayoutdemo;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.v4.widget.SwipeRefreshLayout;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.AbsListView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
 
public class MainActivity extends AppCompatActivity implements AbsListView.OnScrollListener {
 private SwipeRefreshLayout swipeRefreshLayout;
 private ListView lv;
 private ArrayAdapter adapter;
 private List<String> list;
 private View footerView;
 private Handler handler = new Handler(){
  @Override
  public void handleMessage(Message msg) {
   super.handleMessage(msg);
   switch (msg.what){
    case 0x101:
     if (swipeRefreshLayout.isRefreshing()){
      adapter.notifyDataSetChanged();
      swipeRefreshLayout.setRefreshing(false);//设置不刷新
     }

     break;
   }
  }
 };

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  swipeRefreshLayout = (SwipeRefreshLayout) findViewById(R.id.main_srl);
  lv = (ListView) findViewById(R.id.main_lv);
  footerView = getLayoutInflater().inflate(R.layout.loading_layout,null);
  lv.addFooterView(footerView);
  lv.setOnScrollListener(this);
  list = new ArrayList<>();
  list.addAll(Arrays.asList("Java","php","C++","C#","IOS","html","C","J2ee","j2se","VB",".net","Http","tcp","udp","www"));
  adapter = new ArrayAdapter(this,android.R.layout.simple_list_item_1,
  android.R.id.text1,list);

  lv.setAdapter(adapter);
  swipeRefreshLayout.setColorSchemeResources(android.R.color.holo_blue_bright, android.R.color.holo_green_light,
   android.R.color.holo_orange_light, android.R.color.holo_red_light);
  swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
   @Override
   public void onRefresh() {
    new LoadDataThread().start();
   }
  });
 }
 private int visibleLastIndex;//用来可显示的最后一条数据的索引
 @Override
 public void onScrollStateChanged(AbsListView view, int scrollState) {
  if(adapter.getCount() == visibleLastIndex && scrollState == SCROLL_STATE_IDLE){
   new LoadDataThread().start();
  }

 }

 

 @Override
 public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
  visibleLastIndex = firstVisibleItem + visibleItemCount - 1;//减去最后一个加载中那条

 }
 /**
  * 模拟加载数据的线程
  */
 class LoadDataThread extends Thread{
  @Override
  public void run() {
   initData();
   try {
    Thread.sleep(2000);
   } catch (InterruptedException e) {
    e.printStackTrace();
   }
   handler.sendEmptyMessage(0x101);//通过handler发送一个更新数据的标记
  }
 private void initData() {
   list.addAll(Arrays.asList("Json","XML","UDP","http"));

  }
 }
} 


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