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21天学习android开发教程之MediaPlayer

2020-04-11 10:51:15
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本文介绍MediaPlayer的使用。MediaPlayer可以播放音频和视频,另外也可以通过VideoView来播放视频,虽然VideoView比MediaPlayer简单易用,但定制性不如用MediaPlayer,要视情况选择了。MediaPlayer播放音频比较简单,但是要播放视频就需要SurfaceView。SurfaceView比普通的自定义View更有绘图上的优势,它支持完全的OpenGL ES库。
先贴出本文程序运行结果的截图,上面是播放/停止音频,可用SeekBar来调进度,下面是播放/停止视频,也是用SeekBar来调进度:

main.xml的源码:

<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">  <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="播放音频">    <button android:id="@+id/Button02" android:layout_width="wrap_content"       android:layout_height="wrap_content" android:text="停止播放">    <seekbar android:id="@+id/SeekBar02" android:layout_height="wrap_content"     android:layout_width="fill_parent">  <surfaceview android:id="@+id/SurfaceView01"     android:layout_width="fill_parent" android:layout_height="250px">  <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="播放视频">    <button android:layout_width="wrap_content"       android:layout_height="wrap_content" android:text="停止播放" android:id="@+id/Button04">

本文程序的源码,有点长:

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;//互斥变量,防止定时器与SeekBar拖动时进度冲突  @Override  public void onCreate(Bundle savedInstanceState) {   super.onCreate(savedInstanceState);   setContentView(R.layout.main);     //----------Media控件设置---------//  m=new MediaPlayer();    //播放结束之后弹出提示  m.setOnCompletionListener(new MediaPlayer.OnCompletionListener(){      @Override      public void onCompletion(MediaPlayer arg0) {        Toast.makeText(testMedia.this, "结束", 1000).show();        m.release();      }  });    //----------定时器记录播放进度---------//  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); }    /* * 按键事件处理 */ class ClickEvent implements View.OnClickListener{  @Override  public void onClick(View v) {    if(v==btn_start_audio)    {      m.reset();//恢复到未初始化的状态      m=MediaPlayer.create(testMedia.this, R.raw.big);//读取音频      skb_audio.setMax(m.getDuration());//设置SeekBar的长度      try {                  m.prepare();  //准备      } 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();//恢复到未初始化的状态      m=MediaPlayer.create(testMedia.this, R.raw.test);//读取视频      skb_video.setMax(m.getDuration());//设置SeekBar的长度      m.setAudioStreamType(AudioManager.STREAM_MUSIC);      m.setDisplay(surfaceHolder);//设置屏幕            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进度改变事件 */ 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;    }    }}

以上就是21天学习android开发教程第一篇关于MediaPlayer的相关介绍,希望对大家的学习有所帮助。

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