Android构建音频播放器课程(四)

Android构建音频播放器教程(四)
  

11.更新AndroidManifest.xml文件添加android:configChanges=”keyboardHidden|orientation”， AndroidManifest.xml<?xml version="1.0"encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.androidhive.musicplayer"    android:versionCode="1"    android:versionName="1.0">     <uses-sdk android:minSdkVersion="8"/>     <application        android:icon="@drawable/ic_launcher"        android:label="@string/app_name">        <activity            android:name=".AndroidBuildingMusicPlayerActivity"            android:label="@string/app_name"            android:configChanges="keyboardHidden|orientation">            <intent-filter>                <action android:name="android.intent.action.MAIN"/>                 <category android:name="android.intent.category.LAUNCHER"/>            </intent-filter>        </activity>         <activity            android:name=".PlayListActivity"/>    </application> </manifest><!-- AndroidBuildingMusicPlayerActivity -->
  

12.最后的代码  下面是AndroidBuildingMusicPlayerActivity类的完整代码AndroidBuildingMusicPlayerActivity.javapackagecom.androidhive.musicplayer; importjava.io.IOException;importjava.util.ArrayList;importjava.util.HashMap;importjava.util.Random; importandroid.app.Activity;importandroid.content.Intent;importandroid.media.MediaPlayer;importandroid.media.MediaPlayer.OnCompletionListener;importandroid.os.Bundle;importandroid.os.Handler;importandroid.view.View;importandroid.widget.ImageButton;importandroid.widget.SeekBar;importandroid.widget.TextView;importandroid.widget.Toast; publicclassAndroidBuildingMusicPlayerActivityextendsActivityimplementsOnCompletionListener, SeekBar.OnSeekBarChangeListener {     privateImageButton btnPlay;    privateImageButton btnForward;    privateImageButton btnBackward;    privateImageButton btnNext;    privateImageButton btnPrevious;    privateImageButton btnPlaylist;    privateImageButton btnRepeat;    privateImageButton btnShuffle;    privateSeekBar songProgressBar;    privateTextView songTitleLabel;    privateTextView songCurrentDurationLabel;    privateTextView songTotalDurationLabel;    // Media Player    private MediaPlayer mp;    // Handler to update UI timer, progress bar etc,.    privateHandler mHandler = newHandler();;    privateSongsManager songManager;    privateUtilities utils;    privateintseekForwardTime =5000;// 5000 milliseconds    privateintseekBackwardTime =5000;// 5000 milliseconds    privateintcurrentSongIndex =0;    privatebooleanisShuffle =false;    privatebooleanisRepeat =false;    privateArrayList<HashMap<String, String>> songsList = newArrayList<HashMap<String, String>>();     @Override    publicvoidonCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.player);         // All player buttons        btnPlay = (ImageButton) findViewById(R.id.btnPlay);        btnForward = (ImageButton) findViewById(R.id.btnForward);        btnBackward = (ImageButton) findViewById(R.id.btnBackward);        btnNext = (ImageButton) findViewById(R.id.btnNext);        btnPrevious = (ImageButton) findViewById(R.id.btnPrevious);        btnPlaylist = (ImageButton) findViewById(R.id.btnPlaylist);        btnRepeat = (ImageButton) findViewById(R.id.btnRepeat);        btnShuffle = (ImageButton) findViewById(R.id.btnShuffle);        songProgressBar = (SeekBar) findViewById(R.id.songProgressBar);        songTitleLabel = (TextView) findViewById(R.id.songTitle);        songCurrentDurationLabel = (TextView) findViewById(R.id.songCurrentDurationLabel);        songTotalDurationLabel = (TextView) findViewById(R.id.songTotalDurationLabel);         // Mediaplayer        mp =newMediaPlayer();        songManager =newSongsManager();        utils =newUtilities();         // Listeners        songProgressBar.setOnSeekBarChangeListener(this);// Important        mp.setOnCompletionListener(this);// Important         // Getting all songs list        songsList = songManager.getPlayList();         // By default play first song        playSong(0);         /**         * Play button click event         * plays a song and changes button to pause image         * pauses a song and changes button to play image         * */        btnPlay.setOnClickListener(newView.OnClickListener() {             @Override            publicvoidonClick(View arg0) {                // check for already playing                if(mp.isPlaying()){                    if(mp!=null){                        mp.pause();                        // Changing button image to play button                        btnPlay.setImageResource(R.drawable.btn_play);                    }                }else{                    // Resume song                    if(mp!=null){                        mp.start();                        // Changing button image to pause button                        btnPlay.setImageResource(R.drawable.btn_pause);                    }                }             }        });         /**         * Forward button click event         * Forwards song specified seconds         * */        btnForward.setOnClickListener(newView.OnClickListener() {             @Override            publicvoidonClick(View arg0) {                // get current song position                intcurrentPosition = mp.getCurrentPosition();                // check if seekForward time is lesser than song duration                if(currentPosition + seekForwardTime <= mp.getDuration()){                    // forward song                    mp.seekTo(currentPosition + seekForwardTime);                }else{                    // forward to end position                    mp.seekTo(mp.getDuration());                }            }        });         /**         * Backward button click event         * Backward song to specified seconds         * */        btnBackward.setOnClickListener(newView.OnClickListener() {             @Override            publicvoidonClick(View arg0) {                // get current song position                intcurrentPosition = mp.getCurrentPosition();                // check if seekBackward time is greater than 0 sec                if(currentPosition - seekBackwardTime >= 0){                    // forward song                    mp.seekTo(currentPosition - seekBackwardTime);                }else{                    // backward to starting position                    mp.seekTo(0);                }             }        });         /**         * Next button click event         * Plays next song by taking currentSongIndex + 1         * */        btnNext.setOnClickListener(newView.OnClickListener() {             @Override            publicvoidonClick(View arg0) {                // check if next song is there or not                if(currentSongIndex < (songsList.size() - 1)){                    playSong(currentSongIndex +1);                    currentSongIndex = currentSongIndex +1;                }else{                    // play first song                    playSong(0);                    currentSongIndex =0;                }             }        });         /**         * Back button click event         * Plays previous song by currentSongIndex - 1         * */        btnPrevious.setOnClickListener(newView.OnClickListener() {             @Override            publicvoidonClick(View arg0) {                if(currentSongIndex > 0){                    playSong(currentSongIndex -1);                    currentSongIndex = currentSongIndex -1;                }else{                    // play last song                    playSong(songsList.size() -1);                    currentSongIndex = songsList.size() -1;                }             }        });         /**         * Button Click event for Repeat button         * Enables repeat flag to true         * */        btnRepeat.setOnClickListener(newView.OnClickListener() {             @Override            publicvoidonClick(View arg0) {                if(isRepeat){                    isRepeat =false;                    Toast.makeText(getApplicationContext(),"Repeat is OFF", Toast.LENGTH_SHORT).show();                    btnRepeat.setImageResource(R.drawable.btn_repeat);                }else{                    // make repeat to true                    isRepeat =true;                    Toast.makeText(getApplicationContext(),"Repeat is ON", Toast.LENGTH_SHORT).show();                    // make shuffle to false                    isShuffle =false;                    btnRepeat.setImageResource(R.drawable.btn_repeat_focused);                    btnShuffle.setImageResource(R.drawable.btn_shuffle);                }            }        });         /**         * Button Click event for Shuffle button         * Enables shuffle flag to true         * */        btnShuffle.setOnClickListener(newView.OnClickListener() {             @Override            publicvoidonClick(View arg0) {                if(isShuffle){                    isShuffle =false;                    Toast.makeText(getApplicationContext(),"Shuffle is OFF", Toast.LENGTH_SHORT).show();                    btnShuffle.setImageResource(R.drawable.btn_shuffle);                }else{                    // make repeat to true                    isShuffle=true;                    Toast.makeText(getApplicationContext(),"Shuffle is ON", Toast.LENGTH_SHORT).show();                    // make shuffle to false                    isRepeat =false;                    btnShuffle.setImageResource(R.drawable.btn_shuffle_focused);                    btnRepeat.setImageResource(R.drawable.btn_repeat);                }            }        });         /**         * Button Click event for Play list click event         * Launches list activity which displays list of songs         * */        btnPlaylist.setOnClickListener(newView.OnClickListener() {             @Override            publicvoidonClick(View arg0) {                Intent i =newIntent(getApplicationContext(), PlayListActivity.class);                startActivityForResult(i,100);            }        });     }     /**     * Receiving song index from playlist view     * and play the song     * */    @Override    protectedvoidonActivityResult(intrequestCode,                                     intresultCode, Intent data) {        super.onActivityResult(requestCode, resultCode, data);        if(resultCode == 100){             currentSongIndex = data.getExtras().getInt("songIndex");             // play selected song             playSong(currentSongIndex);        }     }     /**     * Function to play a song     * @param songIndex - index of song     * */    publicvoid playSong(intsongIndex){        // Play song        try{            mp.reset();            mp.setDataSource(songsList.get(songIndex).get("songPath"));            mp.prepare();            mp.start();            // Displaying Song title            String songTitle = songsList.get(songIndex).get("songTitle");            songTitleLabel.setText(songTitle);             // Changing Button Image to pause image            btnPlay.setImageResource(R.drawable.btn_pause);             // set Progress bar values            songProgressBar.setProgress(0);            songProgressBar.setMax(100);             // Updating progress bar            updateProgressBar();        }catch(IllegalArgumentException e) {            e.printStackTrace();        }catch(IllegalStateException e) {            e.printStackTrace();        }catch(IOException e) {            e.printStackTrace();        }    }     /**     * Update timer on seekbar     * */    publicvoidupdateProgressBar() {        mHandler.postDelayed(mUpdateTimeTask,100);    }       /**     * Background Runnable thread     * */    privateRunnable mUpdateTimeTask = newRunnable() {           publicvoidrun() {               longtotalDuration = mp.getDuration();               longcurrentDuration = mp.getCurrentPosition();                // Displaying Total Duration time               songTotalDurationLabel.setText(""+utils.milliSecondsToTimer(totalDuration));               // Displaying time completed playing               songCurrentDurationLabel.setText(""+utils.milliSecondsToTimer(currentDuration));                // Updating progress bar               intprogress = (int)(utils.getProgressPercentage(currentDuration, totalDuration));               //Log.d("Progress", ""+progress);               songProgressBar.setProgress(progress);                // Running this thread after 100 milliseconds               mHandler.postDelayed(this,100);           }        };     /**     *     * */    @Override    publicvoidonProgressChanged(SeekBar seekBar,intprogress,booleanfromTouch) {     }     /**     * When user starts moving the progress handler     * */    @Override    publicvoidonStartTrackingTouch(SeekBar seekBar) {        // remove message Handler from updating progress bar        mHandler.removeCallbacks(mUpdateTimeTask);    }     /**     * When user stops moving the progress hanlder     * */    @Override    publicvoidonStopTrackingTouch(SeekBar seekBar) {        mHandler.removeCallbacks(mUpdateTimeTask);        inttotalDuration = mp.getDuration();        intcurrentPosition = utils.progressToTimer(seekBar.getProgress(), totalDuration);         // forward or backward to certain seconds        mp.seekTo(currentPosition);         // update timer progress again        updateProgressBar();    }     /**     * On Song Playing completed     * if repeat is ON play same song again     * if shuffle is ON play random song     * */    @Override    publicvoidonCompletion(MediaPlayer arg0) {         // check for repeat is ON or OFF        if(isRepeat){            // repeat is on play same song again            playSong(currentSongIndex);        }elseif(isShuffle){            // shuffle is on - play a random song            Random rand =newRandom();            currentSongIndex = rand.nextInt((songsList.size() -1) -0+1) +0;            playSong(currentSongIndex);        }else{            // no repeat or shuffle ON - play next song            if(currentSongIndex < (songsList.size() - 1)){                playSong(currentSongIndex +1);                currentSongIndex = currentSongIndex +1;            }else{                // play first song                playSong(0);                currentSongIndex =0;            }        }    }     @Override     publicvoidonDestroy(){     super.onDestroy();        mp.release();     } } 

 14.往模拟器SDCard里添加mp3文件(用于测试)  最后，我们需要往模拟器里面添加几首歌曲用来播放。  1.在用你的Android模拟器来测试这个程序，你需要加载一些歌曲到你的模拟器。您可以使用adb工具，它往Android SDK模拟器SD卡发送文件。
导航到你的Android SDK文件夹/平台工具/使用命令行。和使用push命令，您可以发送文件到SD卡。 （开始你的模拟器执行推送命令之前）
platform-tools> adb push "c:\Songs\White Flag.mp3" "/sdcard/"

 15.运行
  运行我们的程序，效果如下：