Android之MediaPlayer播放音樂並實現進度條執行個體

首先，說明我們是從sd卡裡讀檔案，來播放檔案！！

1、：

提前工作，往sd卡裡放音樂檔案，

2、布局檔案main.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="vertical" ><TextView     android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:text="歌曲名："/><TextView     android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:text="blueflawer.mp3"/><Button     android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:text="播放"    android:id="@+id/play_pause"/><Button     android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:text="重設"    android:id="@+id/reset"/><SeekBar     android:layout_width="fill_parent"    android:layout_height="wrap_content"    android:id="@+id/seekbar"/></LinearLayout>

3、activity類

package cn.csdn.activity;import java.io.File;import java.io.IOException;import java.util.Timer;import java.util.TimerTask;import android.app.Activity;import android.media.MediaPlayer;import android.os.Bundle;import android.os.Environment;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.SeekBar;import android.widget.SeekBar.OnSeekBarChangeListener;public class MyPlayerActivity extends Activity {private Button play_pause, reset;private SeekBar seekbar;private boolean ifplay = false;private MediaPlayer player = null;private String musicName = "blueflawer.mp3";private boolean iffirst = false;private Timer mTimer;  private TimerTask mTimerTask; private boolean isChanging=false;//互斥變數，防止定時器與SeekBar拖動時進度衝突 public void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);player = new MediaPlayer();findViews();// 各組件}private void findViews() {play_pause = (Button) findViewById(R.id.play_pause);reset = (Button) findViewById(R.id.reset);play_pause.setOnClickListener(new MyClick());reset.setOnClickListener(new MyClick());seekbar = (SeekBar) findViewById(R.id.seekbar);seekbar.setOnSeekBarChangeListener(new MySeekbar());}class MyClick implements OnClickListener {public void onClick(View v) {File file = new File(Environment.getExternalStorageDirectory(),musicName);// 判斷有沒有要播放的檔案if (file.exists()) {switch (v.getId()) {case R.id.play_pause:if (player != null && !ifplay) {play_pause.setText("暫停");if (!iffirst) {player.reset();try {player.setDataSource(file.getAbsolutePath());player.prepare();// 準備} catch (IllegalArgumentException e) {e.printStackTrace();} catch (IllegalStateException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}seekbar.setMax(player.getDuration());//設定進度條//----------定時器記錄播放進度---------//          mTimer = new Timer();          mTimerTask = new TimerTask() {              @Override              public void run() {                   if(isChanging==true) {                     return;                  }                seekbar.setProgress(player.getCurrentPosition());            }          };         mTimer.schedule(mTimerTask, 0, 10); iffirst=true;}player.start();// 開始ifplay = true;} else if (ifplay) {play_pause.setText("繼續");player.pause();ifplay = false;}break;case R.id.reset:if (ifplay) {player.seekTo(0);} else {player.reset();try {player.setDataSource(file.getAbsolutePath());player.prepare();// 準備player.start();// 開始} catch (IllegalArgumentException e) {e.printStackTrace();} catch (IllegalStateException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}}break;}}}}//進度條處理class MySeekbar implements OnSeekBarChangeListener {public void onProgressChanged(SeekBar seekBar, int progress,boolean fromUser) {}public void onStartTrackingTouch(SeekBar seekBar) {isChanging=true;  }public void onStopTrackingTouch(SeekBar seekBar) {player.seekTo(seekbar.getProgress());isChanging=false;  }}//來電處理protected void onDestroy() {if(player != null){if(player.isPlaying()){player.stop();}player.release();}super.onDestroy();}protected void onPause() {if(player != null){if(player.isPlaying()){player.pause();}}super.onPause();}protected void onResume() {if(player != null){if(!player.isPlaying()){player.start();}}super.onResume();}}