SeekBar实现音量调节.doc

SeekBar实现音量调节 (/lissdy/article/details/7019522)SeekBar可以通过滑块的位置来标识数值-而且拖动条允许用户拖动滑块来改变值，因此拖动条通常用于对系统的某种数值进行调节，比如调节音量等。SeekBar允许用户改变拖动条的滑块外观，改变滑块外观通常通过如下属性来指定： android:thumb: 指定一个Drawable对象，该对象将自定义滑块。为了让程序能响应拖动条滑块位置的改变，程序可以考虑为它绑定一个OnSeekBarChangeListener监听器。以下是一个使用SeekBar来调节系统音量的实例：XML代码： /滑块样式seekbar_style.xml: thumb.xml: bacon_seekbar.xml: JAVA代码：public class PianoActivity extends Activity /* Called when the activity is first created. */private ImageButton imageButton_white1;private MediaPlayer mediaPlayer01;public AudioManager audiomanage;private TextView mVolume ; /显示当前音量public SeekBar soundBar;private int maxVolume, currentVolume; private int volume=0; /初始化声音Override public void onCreate(Bundle savedInstanceState) super.onCreate(savedInstanceState); setContentView(R.layout.main); mediaPlayer01 = new MediaPlayer(); imageButton_white1=(ImageButton)findViewById(R.id.white1); final SeekBar soundBar=(SeekBar)findViewById(R.id.sound); /音量设置 mVolume = (TextView)findViewById(R.id.mVolume); audiomanage = (AudioManager)getSystemService(Context.AUDIO_SERVICE); maxVolume = audiomanage.getStreamMaxVolume(AudioManager.STREAM_MUSIC); /获取系统最大音量 soundBar.setMax(maxVolume); /拖动条最高值与系统最大声匹配 currentVolume = audiomanage.getStreamVolume(AudioManager.STREAM_MUSIC); /获取当前值 soundBar.setProgress(currentVolume); mVolume.setText(currentVolume*100/maxVolume + %); soundBar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() /调音监听器 public void onProgressChanged(SeekBar arg0,int progress,boolean fromUser) audiomanage.setStreamVolume(AudioManager.STREAM_MUSIC, progress, 0); currentVolume = audiomanage.getStreamVolume(AudioManager.STREAM_MUSIC); /获取当前值 soundBar.setProgress(currentVolume); mVolume.setText(currentVolume*100/maxVolume + %); Override public void onStartTrackingTouch(SeekBar seekBar) / TODO Auto-generated method stub Overridepublic void onSt