android - 使用按钮控制音量

Question

我希望能够使用屏幕按钮(加号和减号)控制音量

我在 OnClick 方法中使用以下内容:

        case R.id.bMinus:
        currentRingerVolume = audioManager.getStreamVolume(AudioManager.STREAM_RING);
        newvolume(-1);
        audioManager.setStreamVolume(AudioManager.STREAM_MUSIC,
                volume, 0);
        break;
    case R.id.bPlus:
        currentRingerVolume = audioManager.getStreamVolume(AudioManager.STREAM_RING);
        newvolume(1);
        audioManager.setStreamVolume(AudioManager.STREAM_MUSIC,
                volume, 0);

newvolume 是我想使用的方法，所以我不会低于音量 0 或高于最大音量

private void newvolume(int i) {

    /*

    currentRingerVolume = audioManager.getStreamVolume(AudioManager.STREAM_RING);
    maxRingerVolume = audioManager.getStreamMaxVolume(AudioManager.STREAM_RING);


     */
    if(volume != maxRingerVolume){
        volume = currentRingerVolume + i;
        volumeInt.setText(volume.toString());
        Log.v("tag ", "v:" + volume + " cv:" + currentRingerVolume);

    }
    if (currentRingerVolume == 0 && i == -1){
        volume = 0;
        volumeInt.setText(currentRingerVolume.toString());
        Log.v("tag ", "v:" + volume + " cv:" + currentRingerVolume);

    }
}

在 logcat 中，我的 cv (currentRingerVolume) 始终为 8，而我的 v(Volume) 仅在 5-8 之间变化

我也在 logcat 中得到这个

12908-12914/com.asdf.wasd D/dalvikvm﹕ JIT code cache reset in 0 ms (4096 bytes 2/0)
    01-19 13:35:11.779  12908-12914/com.asdf.wasd D/dalvikvm﹕ GC_EXPLICIT freed 1204K, 29% free 19409K/27312K, paused 7ms+14ms, total 103ms
    01-19 13:35:12.940  12908-12914/com.asdf.wasd I/dalvikvm﹕ hprof: dumping heap strings to "[DDMS]".
    01-19 13:35:17.224  12908-12914/com.asdf.wasd I/dalvikvm﹕ hprof: heap dump completed (20349KB)
    01-19 13:35:17.244  12908-12908/com.adsf.wasd I/Choreographer﹕ Skipped 300 frames!  The application may be doing too much work on its main thread.

任何帮助将不胜感激

Answer 1

更改您的代码以设置您从中获取的同一流的音量:

case R.id.bMinus:
    currentRingerVolume = audioManager.getStreamVolume(AudioManager.STREAM_RING);
    newvolume(-1);
    audioManager.setStreamVolume(AudioManager.STREAM_RING,
            volume, 0);
    break;
case R.id.bPlus:
    currentRingerVolume = audioManager.getStreamVolume(AudioManager.STREAM_RING);
    newvolume(1);
    audioManager.setStreamVolume(AudioManager.STREAM_RING,
            volume, 0);

此外，如果当前音量处于最大值并且您正试图降低音量，则此音量调整代码将不起作用。更改为:

if((volume != maxRingerVolume) || (i == -1)){
    volume = currentRingerVolume + i;
    volumeInt.setText(volume.toString());
    Log.v("tag ", "v:" + volume + " cv:" + currentRingerVolume);

}

一种更易于阅读的重新排列代码的方法可能是这样的:

volume = currentRingerVolume + i; // apply change
if(volume > maxRingerVolume)
    volume = maxRingerVolume;   // clamp to max
if(volume < 0)
    volume = 0; // clamp to min

// output debug information:
volumeInt.setText(volume.toString());
Log.v("tag ", "v:" + volume + " cv:" + currentRingerVolume);