android中的多媒体应用MediaPlayer

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。

 

迷你音乐播放器

/Chapter11_Media_MiniPlayer/src/com/amaker/test/MainActivity.java

代码

package com.amaker.test;

import android.app.Activity;
import android.app.AlertDialog;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageButton;

public class MainActivity extends Activity implements MediaPlayer.OnCompletionListener {

private ImageButton play,pause,stop;
private MediaPlayer mp;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

play = (ImageButton)findViewById(R.id.play);
pause = (ImageButton)findViewById(R.id.pause);
stop = (ImageButton)findViewById(R.id.stop);

play.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
play();
}
});

pause.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
pause();
}
});

stop.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
stop();
}
});

setup();
}

@Override
public void onDestroy() {
super.onDestroy();
if (stop.isEnabled()) {
stop();
}
}

public void onCompletion(MediaPlayer mp) {
stop();
}

private void play() {
mp.start();

play.setEnabled(false);
pause.setEnabled(true);
stop.setEnabled(true);
}

private void stop() {
mp.stop();
pause.setEnabled(false);
stop.setEnabled(false);

try {
mp.prepare();
mp.seekTo(0);
play.setEnabled(true);
}
catch (Throwable t) {
error(t);
}
}

private void pause() {
mp.pause();
play.setEnabled(true);
pause.setEnabled(false);
stop.setEnabled(true);
}

private void loadClip() {
try {
mp=MediaPlayer.create(this, R.raw.test);
mp.setOnCompletionListener(this);
}
catch (Throwable t) {
error(t);
}
}

private void setup() {
loadClip();
play.setEnabled(true);
pause.setEnabled(false);
stop.setEnabled(false);
}

private void error(Throwable t) {
AlertDialog.Builder builder=new AlertDialog.Builder(this);
builder
.setTitle("报错啦!")
.setMessage(t.toString())
.setPositiveButton("确定", null)
.show();
}
}

/Chapter11_Media_MiniPlayer/res/layout/main.xml

代码

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent">

<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="迷你音乐播放器" />

<LinearLayout
android:orientation="horizontal" android:layout_width="fill_parent"
android:layout_height="fill_parent">

<ImageButton
android:id="@+id/play"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/play"
/>

<ImageButton
android:id="@+id/pause"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/pause"
/>

<ImageButton
android:id="@+id/stop"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/stop"
/>
</LinearLayout>
</LinearLayout>

/Chapter11_Media_MiniPlayer/AndroidManifest.xml

代码

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.amaker.test"
android:versionCode="1"
android:versionName="1.0">
<application android:icon="@drawable/icon" android:label="@string/app_name">
<activity android:name=".MainActivity"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>

</application>
<uses-sdk android:minSdkVersion="3" />

</manifest>