Android 的 MediaPlayer 多媒體播放器
MediaPlayer 可以播放音頻和視頻，另外也可以通過VideoView來播放視頻，雖然VideoView比MediaPlayer簡單易用，但定制性不如用 MediaPlayer，要視情況選擇了。MediaPlayer播放音頻比較簡單，但是要播放視頻就需要SurfaceView。 SurfaceView比普通的自定義View更有繪圖上的優勢，它支持完全的OpenGL ES庫。
main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:id="@+id/LinearLayout01"
android:layout_width="fill_parent" android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical">
<SeekBar android:id="@+id/SeekBar01" android:layout_height="wrap_content"
android:layout_width="fill_parent"></SeekBar>
<LinearLayout android:id="@+id/LinearLayout02"
android:layout_width="wrap_content" android:layout_height="wrap_content">
<Button android:id="@+id/Button01" android:layout_width="wrap_content"
android:layout_height="wrap_content" android:text="播放音頻"></Button>
<Button android:id="@+id/Button02" android:layout_width="wrap_content"
android:layout_height="wrap_content" android:text="停止播放"></Button>
</LinearLayout>
<SeekBar android:id="@+id/SeekBar02" android:layout_height="wrap_content"
android:layout_width="fill_parent"></SeekBar>
<SurfaceView android:id="@+id/SurfaceView01"
android:layout_width="fill_parent" android:layout_height="250px"></SurfaceView>
<LinearLayout android:id="@+id/LinearLayout02"
android:layout_width="wrap_content" android:layout_height="wrap_content">
<Button android:layout_width="wrap_content"
android:layout_height="wrap_content" android:id="@+id/Button03"
android:text="播放視頻"></Button>
<Button android:layout_width="wrap_content"
android:layout_height="wrap_content" android:text="停止播放" android:id="@+id/Button04"></Button>
</LinearLayout>
</LinearLayout></pre>
package com.testMedia;
import java.io.IOException;
import java.util.Timer;
import java.util.TimerTask;
import android.app.Activity;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Button;
import android.widget.SeekBar;
import android.widget.Toast;
public class TestMedia extends Activity {
/* Called when the activity is first created. /
private SeekBar skb_audio=null;
private Button btn_start_audio = null;
private Button btn_stop_audio = null;
private SeekBar skb_video=null;
private Button btn_start_video = null;
private Button btn_stop_video = null;
private SurfaceView surfaceView;
private SurfaceHolder surfaceHolder;
private MediaPlayer m = null;
private Timer mTimer;
private TimerTask mTimerTask;
private boolean isChanging=false;//互斥變量，防止定時器與SeekBar拖動時進度沖突
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//----------Media控件設置---------//
m=new MediaPlayer();
//播放結束之后彈出提示
m.setOnCompletionListener(new MediaPlayer.OnCompletionListener(){
@Override
public void onCompletion(MediaPlayer arg0) {
Toast.makeText(testMedia.this, "結束", 1000).show();
m.release();
}
});
//----------定時器記錄播放進度---------//
mTimer = new Timer();
mTimerTask = new TimerTask() {
@Override
public void run() {
if(isChanging==true)
return;
if(m.getVideoHeight()==0)
skb_audio.setProgress(m.getCurrentPosition());
else
skb_video.setProgress(m.getCurrentPosition());
}
};
mTimer.schedule(mTimerTask, 0, 10);
btn_start_audio = (Button) this.findViewById(R.id.Button01);
btn_stop_audio = (Button) this.findViewById(R.id.Button02);
btn_start_audio.setOnClickListener(new ClickEvent());
btn_stop_audio.setOnClickListener(new ClickEvent());
skb_audio=(SeekBar)this.findViewById(R.id.SeekBar01);
skb_audio.setOnSeekBarChangeListener(new SeekBarChangeEvent());
btn_start_video = (Button) this.findViewById(R.id.Button03);
btn_stop_video = (Button) this.findViewById(R.id.Button04);
btn_start_video.setOnClickListener(new ClickEvent());
btn_stop_video.setOnClickListener(new ClickEvent());
skb_video=(SeekBar)this.findViewById(R.id.SeekBar02);
skb_video.setOnSeekBarChangeListener(new SeekBarChangeEvent());
surfaceView = (SurfaceView) findViewById(R.id.SurfaceView01);
surfaceHolder = surfaceView.getHolder();
surfaceHolder.setFixedSize(100, 100);
surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
/**
按鍵事件處理 */ class ClickEvent implements View.OnClickListener{ @Override public void onClick(View v) { if(v==btn_start_audio) {
m.reset();//恢復到未初始化的狀態 m=MediaPlayer.create(testMedia.this, R.raw.big);//讀取音頻 skb_audio.setMax(m.getDuration());//設置SeekBar的長度 try { m.prepare(); //準備 } catch (IllegalStateException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } m.start(); //播放} else if(v==btn_stop_audio || v==btn_stop_video) {
m.stop();} else if(v==btn_start_video) {
m.reset();//恢復到未初始化的狀態 m=MediaPlayer.create(testMedia.this, R.raw.test);//讀取視頻 skb_video.setMax(m.getDuration());//設置SeekBar的長度 m.setAudioStreamType(AudioManager.STREAM_MUSIC); m.setDisplay(surfaceHolder);//設置屏幕 try { m.prepare(); } catch (IllegalArgumentException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IllegalStateException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } m.start();} } }
/**
SeekBar進度改變事件 */ class SeekBarChangeEvent implements SeekBar.OnSeekBarChangeListener{
@Override public void onProgressChanged(SeekBar seekBar, int progress,
boolean fromUser) {// TODO Auto-generated method stub
}
@Override public void onStartTrackingTouch(SeekBar seekBar) { isChanging=true; }
@Override public void onStopTrackingTouch(SeekBar seekBar) { m.seekTo(seekBar.getProgress()); isChanging=false;
}}
}</pre>
</div>