Android提高第一篇之MediaPlayer
阿新 • • 發佈:2018-11-15
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本文來自http://blog.csdn.net/hellogv/ ,引用必須註明出處!
前面寫了十四篇關於介面的入門文章,大家都看完和跟著練習之後,對於常用的Layout和View都會有一定的瞭解了,接下來的文章就不再強調介紹介面了,而是針對具體的常見功能而展開。
本文介紹MediaPlayer的使用。MediaPlayer可以播放音訊和視訊,另外也可以通過VideoView來播放視訊,雖然VideoView比MediaPlayer簡單易用,但定製性不如用MediaPlayer,要視情況選擇了。MediaPlayer播放音訊比較簡單,但是要播放視訊就需要SurfaceView。SurfaceView比普通的自定義View更有繪圖上的優勢,它支援完全的OpenGL ES庫。
先貼出本文程式執行結果的截圖,上面是播放/停止音訊,可用SeekBar來調進度,下面是播放/停止視訊,也是用SeekBar來調進度:
main.xml的原始碼:
[xhtml] view plain copy print ?
- <?xml version="1.0" encoding="utf-8"?>
- <LinearLayout android:id="@+id/LinearLayout01"
- android:layout_width
- 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="播放音訊"></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="播放視訊"></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>
本文程式的原始碼,有點長:
[java] view plain copy print ?
- 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;//互斥變數,防止定時器與SeekBar拖動時進度衝突
- @Override
- public void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.main);
- //----------Media控制元件設定---------//
- m=new MediaPlayer();
- //播放結束之後彈出提示
- 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);//讀取音訊
- skb_audio.setMax(m.getDuration());//設定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);//讀取視訊
- skb_video.setMax(m.getDuration());//設定SeekBar的長度
- m.setAudioStreamType(AudioManager.STREAM_MUSIC);
- m.setDisplay(surfaceHolder);//設定螢幕
- 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;
- }
- }
- }