android用听筒不断播放音乐

这个小应用常用于测试手机的听筒寿命。

MainActivity:
package morgen.headphone;

import java.io.File;
import android.app.Activity;
import android.content.Context;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnPreparedListener;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity {
private EditText nameText;
private String path;
private MediaPlayer mediaPlayer;

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

mediaPlayer = new MediaPlayer();
nameText = (EditText) this.findViewById(R.id.filename);
}

@Override
protected void onDestroy() {
mediaPlayer.release();
mediaPlayer = null;
super.onDestroy();
}

public void mediaplay(View v) {
switch (v.getId()) {
case R.id.playbutton:
String filename = nameText.getText().toString();
File audio = new File(Environment.getExternalStorageDirectory(), filename);
if (audio.exists()) {
AudioManager audioManager = (AudioManager) this.getSystemService(Context.AUDIO_SERVICE);
audioManager.setMode(AudioManager.MODE_IN_CALL);// 把模式调成听筒放音模式
path = audio.getAbsolutePath();
play(0);
// 设置音频循环播放
mediaPlayer.setLooping(true);
} else {
path = null;
Toast.makeText(getApplicationContext(), R.string.filenoexist, 1).show();
}
break;

case R.id.stopbutton:
if (mediaPlayer.isPlaying())
mediaPlayer.stop();
AudioManager audioManager = (AudioManager) this.getSystemService(Context.AUDIO_SERVICE);
audioManager.setMode(AudioManager.MODE_NORMAL);
break;
}
}

private void play(int position) {
try {
mediaPlayer.reset();// 把各项参数恢复到初始状态
mediaPlayer.setDataSource(path);
mediaPlayer.prepare();// 进行缓冲
mediaPlayer.setOnPreparedListener(new PrepareListener(position));
} catch (Exception e) {
e.printStackTrace();
}
}

private final class PrepareListener implements OnPreparedListener {
private int position;

public PrepareListener(int position) {
this.position = position;
}

public void onPrepared(MediaPlayer mp) {
mediaPlayer.start();// 开始播放
if (position > 0)
mediaPlayer.seekTo(position);
}
}

}

布局文件：
main.xml:
<?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="@string/filename"
    />

    <EditText
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="tianzhao.mp3"
    android:id="@+id/filename"
    />

    <LinearLayout
    android:orientation="horizontal"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    >
     <Button
      android:layout_width="100dip"
      android:layout_height="60dip"
      android:text="@string/playbutton"
      android:onClick="mediaplay"
      android:id="@+id/playbutton"
      />

<Button
     android:layout_width="100dip"
      android:layout_height="60dip"
      android:text="@string/stopbutton"
      android:onClick="mediaplay"
      android:id="@+id/stopbutton"
      />
    </LinearLayout>
</LinearLayout>

strings.xml:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="hello">Hello World, MainActivity!</string>
    <string name="app_name">音乐播放器</string>
    <string name="filename">音乐文件名称</string>
    <string name="playbutton">播放</string>
    <string name="stopbutton">停止</string>
    <string name="filenoexist">文件没有发现</string>
</resources>

最后记得加上权限：
<uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS"/>

摘自：亨利摩根的专栏

补充：移动开发 , Android ,