mediaplayer实现音乐播放

Android Podcast Code Source

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Android Podcast player

工程目录：

UI设计：

UI设计部分只做了简单修改：

• 在TextView1下面由添加了一个TextView2
• imageView中删除了android:src="@raw/pic"

布局效果：

UI布局详细代码

工程代码

wikipodcast2.java package com.emsym.wikipodcast2; import java.io.IOException; import java.io.InputStream; import java.net.HttpURLConnection; import java.net.MalformedURLException; import java.net.URL; import java.util.Iterator; import java.util.LinkedList; import java.util.List; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.parsers.ParserConfigurationException; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.NodeList; import org.xml.sax.SAXException; import android.app.Activity; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.media.MediaPlayer; import android.media.MediaPlayer.OnCompletionListener; import android.net.Uri; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.ImageView; import android.widget.ProgressBar; import android.widget.SeekBar; import android.widget.SeekBar.OnSeekBarChangeListener; import android.widget.TextView; 类成员定义：（有点类似全局变量定义） TextView mTextView; TextView itemTextView; Button startButton; Button pauseButton; Button nextButton; ProgressBar mProgressBar; SeekBar mSeekBar; ImageView mImageView; MediaPlayer mMediaPlayer; int mVol = 50; List itemList = new LinkedList(); Iterator it; 在OnCreat方法中： setContentView()：显示UI布局main.xml widgetsConfigure()：实例化使用的各种窗口部件并进行相应配置（主要是设置各种事件监听器） XMLDOM()：使用DOM对xml文件进行解析 @Override public void onCreate(Bundle savedInstanceState) { String uri = "http://www.voiceblog.jp/katsuhiro/rss2.0.xml"; super.onCreate(savedInstanceState); setContentView(R.layout.main); widgetsConfigure(); XMLDOM(uri); } widgetsConfigure()实例化了各种窗口部件并设置事件监听器，并声明了新建了mMediaPlayer。 public void widgetsConfigure(){ startButton = (Button) findViewById (R.id.startButton); startButton.setOnClickListener(startButtonClicked); pauseButton = (Button) findViewById (R.id.pauseorcontinueButton); pauseButton.setOnClickListener(pauseButtonClicked); nextButton = (Button) findViewById (R.id.nextButton); nextButton.setOnClickListener(nextButtonClicked); mSeekBar = (SeekBar) findViewById (R.id.VolumeSeekBar); mSeekBar.setOnSeekBarChangeListener(mSeekBarChanged); mTextView = (TextView) findViewById (R.id.TextView1); mTextView.setText("Click start to play!"); itemTextView = (TextView) findViewById (R.id.TextView2); mProgressBar = (ProgressBar) findViewById (R.id.MusicProgressBar); mImageView = (ImageView) findViewById (R.id.musicImage); mMediaPlayer = new MediaPlayer(); } startButton点击事件监听器设置 public OnClickListener startButtonClicked = new OnClickListener(){ @Override public void onClick(View v) { // TODO Auto-generated method stub it = itemList.iterator(); if(it.hasNext()){ Item ilist = (Item) it.next(); PlayMusic(ilist); } } }; it = itemList.iterator();构建一个链表的迭代器； 调用函数PlayMusic()来播放音乐。 mMediaPlayer播放结束事件监听器设置 public OnCompletionListener completedPlay = new OnCompletionListener(){ public void onCompletion(MediaPlayer arg0){ PlayNext(); } }; 当播放结束事件被监听到时，则调用函数PlayNext()来播放下一首 函数PlayNext():播放下一首 public void PlayNext(){ if(it.hasNext()){ Item ilist = (Item)it.next(); PlayMusic(ilist); }else{ it = itemList.iterator(); Item ilist = (Item)it.next(); PlayMusic(ilist); } } 播放下一首，首先判断itemList是否还有下一个Item，如果有，则去下一个Item播放； 如果没有，则重置迭代器（从头开始），选择第一个Item来播放 函数PlayMusic():开始播放音乐 public void PlayMusic(Item music){ itemTextView.setText("Title: "+music.title+"\n"); itemTextView.append("Authot: "+ music.author+"\n"); itemTextView.append("PubDate: "+ music.pubDate+"\n"); itemTextView.append("Duration: "+ music.duration+"\n"); Uri uri = Uri.parse(music.url); mMediaPlayer.reset(); //** try{ mMediaPlayer.setDataSource(this, uri); mSeekBar.setProgress(mVol); mMediaPlayer.setVolume((float)(0.01*mVol), (float)(0.01*mVol)); }catch(IllegalStateException e){ }catch(IOException e){ }catch(IllegalArgumentException e){ }catch(SecurityException e){ } try{ mMediaPlayer.prepare(); }catch(IOException e){ } mMediaPlayer.start(); mMediaPlayer.setOnCompletionListener(completedPlay); changeProgressBar(); } 该函数的参数是Item，首先是取出Item中的各个变量，对一些变量进行显示； 然后设置播放的数据源，并调节播放音量和拖动条显示； 设置播放结束事件监听器； 调用函数changeProgressBar()来改变进度条显示； 函数changeProgressBar()：新建线程负责改变进度条 public void changeProgressBar(){ mProgressBar.setMax(mMediaPlayer.getDuration()); new Thread(new Runnable(){ public void run(){ while(true){ mProgressBar.setProgress(mMediaPlayer.getCurrentPosition()); try { Thread.sleep(1000); } catch (InterruptedException e) { // TODO Auto-generated catch block } } } }).start(); } 新建一个线程，根据方法getCurrentPosition()得到的结果来设置进度条的进度 pauseButton点击事件监听器设置 public OnClickListener pauseButtonClicked = new OnClickListener(){ @Override public void onClick(View v) { // TODO Auto-generated method stub if(mMediaPlayer.isPlaying()){ mMediaPlayer.pause(); pauseButton.setText("continue"); }else{ mMediaPlayer.start(); pauseButton.setText("pause"); } } }; nextButton点击事件监听器设置 public OnClickListener nextButtonClicked = new OnClickListener(){ @Override public void onClick(View v) { // TODO Auto-generated method stub PlayNext(); } }; 这个的设置和播放一首结束时一样 mSeekBar改变事件监听器设置 public OnSeekBarChangeListener mSeekBarChanged = new OnSeekBarChangeListener(){ @Override public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) { // TODO Auto-generated method stub mVol = progress; mMediaPlayer.setVolume((float)(0.01*mVol), (float)(0.01*mVol)); } @Override public void onStartTrackingTouch(SeekBar seekBar) { // TODO Auto-generated method stub } @Override public void onStopTrackingTouch(SeekBar seekBar) { // TODO Auto-generated method stub } }; 函数XMLDOM()：对xml文件的DOM解析 public void XMLDOM(String xmlUri){ DocumentBuilderFactory docBuilderFactory = null; DocumentBuilder docBuilder = null; Document doc = null; String TITLE = "title"; String IMAGE = "itunes:image"; String ITEM = "item"; try{ docBuilderFactory = DocumentBuilderFactory.newInstance(); docBuilder = docBuilderFactory.newDocumentBuilder(); doc = docBuilder.parse(xmlUri); Element root = doc.getDocumentElement(); //title Node title = root.getElementsByTagName(TITLE).item(0); mTextView.setText(title.getTextContent()); //image Node image = root.getElementsByTagName(IMAGE).item(0); Element elementImage = (Element) image; String imageUrl =elementImage.getAttribute("href"); mImageView.setImageBitmap(GetNetBitmap(imageUrl)); //Items NodeList items = root.getElementsByTagName(ITEM); for(int i = 0;i

AndroidManifest.xml

由于在程序中是用了网络，所以在AndroidManifest.xml中要添加使用网络的user-permission,使用方法：