手機影音7--視頻播放器的基本功能(4)

1.用AudioManager調聲音

1_得到當前音量和最大音量

//關於設置音量
private int currentVolume;//當前音量值
private int currentMaxVolume;//當前最大音量
private AudioManager am;

am = (AudioManager) getSystemService(AUDIO_SERVICE);     
currentVolume = am.getStreamVolume(AudioManager.STREAM_MUSIC);
currentMaxVolume = am.getStreamMaxVolume(AudioManager.STREAM_MUSIC);

2_拖動的時候改變音量

voice_seekBar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {
       
       @Override
       public void onStopTrackingTouch(SeekBar seekBar) {
          sendDelayedHideControlPlayerMessage();
       }
       
       @Override
       public void onStartTrackingTouch(SeekBar seekBar) {
          removeDelayedHideControlPlayerMessage();
       }
       
       @Override
       public void onProgressChanged(SeekBar seekBar, int progress,
            boolean fromUser) {
          if(fromUser){
            updateVolume(progress);
          }
       }
});


/**
 * 修改音量範圍0~15
 * @param progress2
*/
protected void updateVolume(int volume) {
    am.setStreamVolume(AudioManager.STREAM_MUSIC, volume, 0);
    voice_seekBar.setProgress(volume);   
    currentVolume = volume;
}

3_靜音和非靜音

case R.id.btn_voice:
	isMute = !isMute;
	updateVolume(currentVolume);
break;


/**
 * 修改音量範圍0~15
 * @param progress2
*/
protected void updateVolume(int volume) {
	if(isMute){
		am.setStreamVolume(AudioManager.STREAM_MUSIC, 0, 0);
		voice_seekBar.setProgress(0);
	}else{
		am.setStreamVolume(AudioManager.STREAM_MUSIC, volume, 0);
		voice_seekBar.setProgress(volume);
	} 
	currentVolume = volume;
}

2.手指在屏幕上下滑動實現聲音大小變化　　

private  float startY;
/**
 * 滑動的區域
 */
private float touchRang;
/**
 * 當前的音量
 */
private  int mVol;

@Override
public boolean onTouchEvent(MotionEvent event) {
	switch (event.getAction()){
		case MotionEvent.ACTION_DOWN://手指按下屏幕
			//1.記錄相關的值
			startY = event.getY();
			touchRang =Math.min(screenWidth, screenHeight);//screenHeight
			mVol = am.getStreamVolume(AudioManager.STREAM_MUSIC);
			handler.removeMessages(HIDE_MEDIACONTROL);
			break;
		case MotionEvent.ACTION_MOVE://手指在屏幕上移動
			//2.來到結束的坐標
			float endY = event.getY();
			//3.計算偏移量
			float distanceY = startY - endY;
			//要改變的聲音 = (滑動的距離 / 總距離)*最大音量
			float delta = (distanceY/touchRang)*maxVolume;
			//最終聲音 = 原來的聲音 + 要改變的聲音
			float volum  e = Math.min(Math.max(mVol+delta,0),maxVolume);
			if(delta != 0){
				updatavolumeProgress((int) volume);
			}
			// startY = event.getY();
			break;
		case MotionEvent.ACTION_UP://手指離開屏幕
			handler.sendEmptyMessageDelayed(HIDE_MEDIACONTROL,5000);
			break;
	}
	return super.onTouchEvent(event);
}

3.監聽按手機聲音健改變聲音大小　　

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {

    if(keyCode == KeyEvent.KEYCODE_VOLUME_DOWN){
        currentVolume--;
        updatavolumeProgress(currentVolume);
        handler.removeMessages(HIDE_MEDIACONTROL);
        handler.sendEmptyMessageDelayed(HIDE_MEDIACONTROL, 5000);
        return true;
    }else if(keyCode ==KeyEvent.KEYCODE_VOLUME_UP){
        currentVolume++;
        updatavolumeProgress(currentVolume);
        handler.removeMessages(HIDE_MEDIACONTROL);
        handler.sendEmptyMessageDelayed(HIDE_MEDIACONTROL, 5000);
        return true;
    }

    return super.onKeyDown(keyCode, event);
}