Android開源項目PullToRefresh下拉刷新功能詳解

更新時間：2016年09月22日 09:12:38 作者：Developer_Kale

這篇文章主要為大家詳細介紹了Android開源項目PullToRefresh下拉刷新功能,具有一定的參考價值，感興趣的小伙伴們可以參考一下

先看看效果圖：

開源項地址：https://github.com/chrisbanes/Android-PullToRefresh

下拉刷新這個功能我們都比較常見了，今天介紹的就是這個功能的實現(xiàn)。我將按照這個開源庫的范例來一點一點介紹，今天是介紹比較常見的PullToRefreshListView，是讓listView有下拉刷新功能。

1.下載項目包，將library包導入即可，其他的包暫時不用

2.分析源碼，看我們可以設置的有哪些

<?xml version="1.0" encoding="utf-8"?>
<resources>

 <declare-styleable name="PullToRefresh">

 <!-- A drawable to use as the background of the Refreshable View -->
 <!-- 設置刷新view的背景 -->
 <attr name="ptrRefreshableViewBackground" format="reference|color" />

 <!-- A drawable to use as the background of the Header and Footer Loading Views -->
 <!-- 設置頭部view的背景 -->
 <attr name="ptrHeaderBackground" format="reference|color" />

 <!-- Text Color of the Header and Footer Loading Views -->
 <!-- 設置頭部/底部文字的顏色 -->
 <attr name="ptrHeaderTextColor" format="reference|color" />

 <!-- Text Color of the Header and Footer Loading Views Sub Header -->
 <!-- 設置頭部/底部副標題的文字顏色 -->
 <attr name="ptrHeaderSubTextColor" format="reference|color" />

 <!-- Mode of Pull-to-Refresh that should be used -->
 <!-- 設置下拉刷新的模式，有多重方式可選。無刷新功能，從頂部刷新，從底部刷新，二者都有，只允許手動刷新 -->
 <attr name="ptrMode">
  <flag name="disabled" value="0x0" />
  <flag name="pullFromStart" value="0x1" />
  <flag name="pullFromEnd" value="0x2" />
  <flag name="both" value="0x3" />
  <flag name="manualOnly" value="0x4" />

  <!-- These last two are depreacted -->
  <!-- 這兩個屬性不推薦了，用上面的代替即可 -->
  <flag name="pullDownFromTop" value="0x1" />
  <flag name="pullUpFromBottom" value="0x2" />
 </attr>

 <!-- Whether the Indicator overlay(s) should be used -->
 <!-- 是否顯示指示箭頭 -->
 <attr name="ptrShowIndicator" format="reference|boolean" />

 <!-- Drawable to use as Loading Indicator. Changes both Header and Footer. -->
 <!-- 指示箭頭的圖片 -->
 <attr name="ptrDrawable" format="reference" />

 <!-- Drawable to use as Loading Indicator in the Header View. Overrides value set in ptrDrawable. -->
 <!-- 頂部指示箭頭的圖片，設置后會覆蓋ptrDrawable中頂部的設置 -->
 <attr name="ptrDrawableStart" format="reference" />

 <!-- Drawable to use as Loading Indicator in the Fooer View. Overrides value set in ptrDrawable. -->
 <!-- 底部指示箭頭的圖片，設置后會覆蓋ptrDrawable中底部的設置 -->
 <attr name="ptrDrawableEnd" format="reference" />

 <!-- Whether Android's built-in Over Scroll should be utilised for Pull-to-Refresh. -->
 <attr name="ptrOverScroll" format="reference|boolean" />

 <!-- Base text color, typeface, size, and style for Header and Footer Loading Views -->
 <!-- 設置文字的基本字體 -->
 <attr name="ptrHeaderTextAppearance" format="reference" />

 <!-- Base text color, typeface, size, and style for Header and Footer Loading Views Sub Header -->
 <!-- 設置副標題的基本字體 -->
 <attr name="ptrSubHeaderTextAppearance" format="reference" />

 <!-- Style of Animation should be used displayed when pulling. -->
 <!-- 設置下拉時標識圖的動畫，默認為rotate -->
 <attr name="ptrAnimationStyle">
  <flag name="rotate" value="0x0" />
  <flag name="flip" value="0x1" />
 </attr>

 <!-- Whether the user can scroll while the View is Refreshing -->
 <!-- 設置刷新時是否允許滾動，一般為true -->
 <attr name="ptrScrollingWhileRefreshingEnabled" format="reference|boolean" />

 <!--
  Whether PullToRefreshListView has it's extras enabled. This allows the user to be 
  able to scroll while refreshing, and behaves better. It acheives this by adding
  Header and/or Footer Views to the ListView.
 -->
 <!-- 允許在listview中添加頭/尾視圖 -->
 <attr name="ptrListViewExtrasEnabled" format="reference|boolean" />

 <!--
  Whether the Drawable should be continually rotated as you pull. This only
  takes effect when using the 'Rotate' Animation Style.
 -->
 <!-- 當設置rotate時，可以用這個來設置刷新時旋轉的圖片 -->
 <attr name="ptrRotateDrawableWhilePulling" format="reference|boolean" />

 <!-- BELOW HERE ARE DEPRECEATED. DO NOT USE. -->
 <attr name="ptrAdapterViewBackground" format="reference|color" />
 <attr name="ptrDrawableTop" format="reference" />
 <attr name="ptrDrawableBottom" format="reference" />
 </declare-styleable>

</resources>

看到有這么多可以設置的屬性，別以為真的就可以定制了。真正要定制還得到layout中改變刷新布局

3.開始用它建立自己的工程
設置布局文件
就是插入PullToRefreshListView

<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="${relativePackage}.${activityClass}" 
 android:background="#000000">

<!-- The PullToRefreshListView replaces a standard ListView widget. -->

 <com.handmark.pulltorefresh.library.PullToRefreshListView
 xmlns:ptr="http://schemas.android.com/apk/res-auto"
 android:id="@+id/pull_refresh_list"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 android:cacheColorHint="#000000"
 android:divider="#19000000"
 android:dividerHeight="4dp"
 android:fadingEdge="none"
 android:fastScrollEnabled="false"
 android:footerDividersEnabled="false"
 android:headerDividersEnabled="false"
 android:smoothScrollbar="true" 
 ptr:ptrAnimationStyle="rotate"
 ptr:ptrHeaderTextColor="#ffffff"
 ptr:ptrHeaderSubTextColor="#00ffff"
 ptr:ptrHeaderBackground="@null"
 ptr:ptrDrawable="@drawable/ic_launcher"/>
 
</RelativeLayout>

開始編寫代碼

1.找到這個控件，并且設置監(jiān)聽器

這里面用到了一個日期的工具類，其實就是設置上次下拉的時間的。此外在下拉后會觸發(fā)一個異步任務

 /**
 * 設置下拉刷新的listview的動作
 */
 private void initPTRListView() {
 mPullRefreshListView = (PullToRefreshListView) findViewById(R.id.pull_refresh_list);
 //設置拉動監(jiān)聽器
 mPullRefreshListView.setOnRefreshListener(new OnRefreshListener<ListView>() {

  @Override
  public void onRefresh(PullToRefreshBase<ListView> refreshView) {
  //設置下拉時顯示的日期和時間
  String label = DateUtils.formatDateTime(getApplicationContext(), System.currentTimeMillis(),
   DateUtils.FORMAT_SHOW_TIME | DateUtils.FORMAT_SHOW_DATE | DateUtils.FORMAT_ABBREV_ALL);

  // 更新顯示的label
  refreshView.getLoadingLayoutProxy().setLastUpdatedLabel(label);
  // 開始執(zhí)行異步任務，傳入適配器來進行數(shù)據改變
  new GetDataTask(mPullRefreshListView, mAdapter,mListItems).execute();
  }
 });

 // 添加滑動到底部的監(jiān)聽器
 mPullRefreshListView.setOnLastItemVisibleListener(new OnLastItemVisibleListener() {
  
  @Override
  public void onLastItemVisible() {
  Toast.makeText(getApplication(), "已經到底了", Toast.LENGTH_SHORT).show();
  }
 });
 
 //mPullRefreshListView.isScrollingWhileRefreshingEnabled();//看刷新時是否允許滑動
 //在刷新時允許繼續(xù)滑動
 mPullRefreshListView.setScrollingWhileRefreshingEnabled(true);
 //mPullRefreshListView.getMode();//得到模式
 //上下都可以刷新的模式。這里有兩個選擇：Mode.PULL_FROM_START，Mode.BOTH，PULL_FROM_END
 mPullRefreshListView.setMode(Mode.BOTH);
 
 /**
  * 設置反饋音效
  */
 SoundPullEventListener<ListView> soundListener = new SoundPullEventListener<ListView>(this);
 soundListener.addSoundEvent(State.PULL_TO_REFRESH, R.raw.pull_event);
 soundListener.addSoundEvent(State.RESET, R.raw.reset_sound);
 soundListener.addSoundEvent(State.REFRESHING, R.raw.refreshing_sound);
 mPullRefreshListView.setOnPullEventListener(soundListener);
 }

2.從上面的那個控件中，得到它包含的listView，并且設置適配器

 //普通的listview對象
 private ListView actualListView;
 //添加一個鏈表數(shù)組，來存放string數(shù)組，這樣就可以動態(tài)增加string數(shù)組中的內容了
 private LinkedList<String> mListItems;
 //給listview添加一個普通的適配器
 private ArrayAdapter<String> mAdapter;

這里用到了一個LinkedList的對象，這個是一個類似于ArrayList的鏈表數(shù)組，比較方便在開頭和末尾添加String

 /**
 * 設置listview的適配器
 */
 private void initListView() {
 //通過getRefreshableView()來得到一個listview對象
 actualListView = mPullRefreshListView.getRefreshableView();
 
 String []data = new String[] {"android","ios","wp","java","c++","c#"};
 mListItems = new LinkedList<String>();
 //把string數(shù)組中的string添加到鏈表中
 mListItems.addAll(Arrays.asList(data));
 
 mAdapter = new ArrayAdapter<>(getApplicationContext(), 
  android.R.layout.simple_list_item_1, mListItems);
 actualListView.setAdapter(mAdapter);
 }

3.寫一個異步任務，來模仿從網絡加載數(shù)據

這里要注意的是，加載完后要出發(fā)刷新完成和通知適配器改變的方法

package com.kale.ptrlistviewtest;

import java.util.LinkedList;

import android.os.AsyncTask;
import android.widget.ArrayAdapter;

import com.handmark.pulltorefresh.library.PullToRefreshListView;
import com.handmark.pulltorefresh.library.PullToRefreshBase.Mode;

/**
 * @author:Jack Tony
 * @tips :通過異步任務來加載網絡中的數(shù)據，進行更新
 * @date :2014-10-14
 */
public class GetDataTask extends AsyncTask<Void, Void, Void>{

 private PullToRefreshListView mPullRefreshListView;
 private ArrayAdapter<String> mAdapter;
 private LinkedList<String> mListItems;
 
 public GetDataTask(PullToRefreshListView listView,
  ArrayAdapter<String> adapter,LinkedList<String> listItems) {
 // TODO 自動生成的構造函數(shù)存根
 mPullRefreshListView = listView;
 mAdapter = adapter;
 mListItems = listItems;
 }
 
 @Override
 protected Void doInBackground(Void... params) {
 //模擬請求
 try {
  Thread.sleep(2000);
 } catch (InterruptedException e) {
 }
 return null;
 }
 
 @Override
 protected void onPostExecute(Void result) {
 // TODO 自動生成的方法存根
 super.onPostExecute(result);
 //得到當前的模式
 Mode mode = mPullRefreshListView.getCurrentMode();
 if(mode == Mode.PULL_FROM_START) {
  mListItems.addFirst("這是刷新出來的數(shù)據");
 }
 else {
  mListItems.addLast("這是刷新出來的數(shù)據");
 }
 // 通知數(shù)據改變了
 mAdapter.notifyDataSetChanged();
 // 加載完成后停止刷新
 mPullRefreshListView.onRefreshComplete();
 
 }
 


}

貼上acitivty中的全部代碼

MainActivity.java

package com.kale.ptrlistviewtest;

import java.util.Arrays;
import java.util.LinkedList;

import android.app.Activity;
import android.os.Bundle;
import android.text.format.DateUtils;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

import com.handmark.pulltorefresh.library.PullToRefreshBase;
import com.handmark.pulltorefresh.library.PullToRefreshBase.Mode;
import com.handmark.pulltorefresh.library.PullToRefreshBase.OnLastItemVisibleListener;
import com.handmark.pulltorefresh.library.PullToRefreshBase.OnRefreshListener;
import com.handmark.pulltorefresh.library.PullToRefreshBase.State;
import com.handmark.pulltorefresh.library.PullToRefreshListView;
import com.handmark.pulltorefresh.library.extras.SoundPullEventListener;

public class MainActivity extends Activity {
 
 //一個可以下拉刷新的listView對象
 private PullToRefreshListView mPullRefreshListView;
 //普通的listview對象
 private ListView actualListView;
 //添加一個鏈表數(shù)組，來存放string數(shù)組，這樣就可以動態(tài)增加string數(shù)組中的內容了
 private LinkedList<String> mListItems;
 //給listview添加一個普通的適配器
 private ArrayAdapter<String> mAdapter;
 
 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 
 initView();

 //一打開應用就自動刷新，下面語句可以寫到刷新按鈕里面
 mPullRefreshListView.setRefreshing(true);
 //new GetDataTask(mPullRefreshListView, mAdapter, mListItems).execute();
 //mPullRefreshListView.setRefreshing(false);

 }

 private void initView() {
 initPTRListView();
 initListView();
 }
 
 /**
 * 設置下拉刷新的listview的動作
 */
 private void initPTRListView() {
 mPullRefreshListView = (PullToRefreshListView) findViewById(R.id.pull_refresh_list);
 //設置拉動監(jiān)聽器
 mPullRefreshListView.setOnRefreshListener(new OnRefreshListener<ListView>() {

  @Override
  public void onRefresh(PullToRefreshBase<ListView> refreshView) {
  //設置下拉時顯示的日期和時間
  String label = DateUtils.formatDateTime(getApplicationContext(), System.currentTimeMillis(),
   DateUtils.FORMAT_SHOW_TIME | DateUtils.FORMAT_SHOW_DATE | DateUtils.FORMAT_ABBREV_ALL);

  // 更新顯示的label
  refreshView.getLoadingLayoutProxy().setLastUpdatedLabel(label);
  // 開始執(zhí)行異步任務，傳入適配器來進行數(shù)據改變
  new GetDataTask(mPullRefreshListView, mAdapter,mListItems).execute();
  }
 });

 // 添加滑動到底部的監(jiān)聽器
 mPullRefreshListView.setOnLastItemVisibleListener(new OnLastItemVisibleListener() {
  
  @Override
  public void onLastItemVisible() {
  Toast.makeText(getApplication(), "已經到底了", Toast.LENGTH_SHORT).show();
  }
 });
 
 //mPullRefreshListView.isScrollingWhileRefreshingEnabled();//看刷新時是否允許滑動
 //在刷新時允許繼續(xù)滑動
 mPullRefreshListView.setScrollingWhileRefreshingEnabled(true);
 //mPullRefreshListView.getMode();//得到模式
 //上下都可以刷新的模式。這里有兩個選擇：Mode.PULL_FROM_START，Mode.BOTH，PULL_FROM_END
 mPullRefreshListView.setMode(Mode.BOTH);
 
 /**
  * 設置反饋音效
  */
 SoundPullEventListener<ListView> soundListener = new SoundPullEventListener<ListView>(this);
 soundListener.addSoundEvent(State.PULL_TO_REFRESH, R.raw.pull_event);
 soundListener.addSoundEvent(State.RESET, R.raw.reset_sound);
 soundListener.addSoundEvent(State.REFRESHING, R.raw.refreshing_sound);
 mPullRefreshListView.setOnPullEventListener(soundListener);
 }
 
 /**
 * 設置listview的適配器
 */
 private void initListView() {
 //通過getRefreshableView()來得到一個listview對象
 actualListView = mPullRefreshListView.getRefreshableView();
 
 String []data = new String[] {"android","ios","wp","java","c++","c#"};
 mListItems = new LinkedList<String>();
 //把string數(shù)組中的string添加到鏈表中
 mListItems.addAll(Arrays.asList(data));
 
 mAdapter = new ArrayAdapter<>(getApplicationContext(), 
  android.R.layout.simple_list_item_1, mListItems);
 actualListView.setAdapter(mAdapter);
 }
}

源碼下載：http://xiazai.jb51.net/201609/yuanma/AndroidListView(jb51.net).rar

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持腳本之家。

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