Android Can'；t设置音量，音量控制不会转发到系统

我尝试使用Android

MediaPlayer

框架来播放

mp3

文件 （）

在我设法使它工作之后，我很快意识到，音量上升/下降事件被类

javafxports.android.KeyEventProcessor

捕获，并且从未被转发。我试图避开那件事，但没有成功

是否有任何方法可以将事件发送到系统，使其不被捕获

感谢和问候，

---

丹尼尔

虽然我讨厌不断回答自己的问题，但在玩了几个小时安卓API、翻阅了一些文档等之后，我找到了一个解决方案

我的解决方案部分基于@josé-pereda给出的答案

我为任务“volumeUp”、“volumeDown”和“静音”创建了一个界面：

然后，基于以下关于如何设置的答案，我在Android上提出了以下实现：

import java.util.ArrayList;
import java.util.logging.Logger;

import android.content.Context;
import android.media.AudioManager;
import android.view.KeyEvent;
import android.view.View;
import android.view.ViewGroup;
import my.package.platform.NativeVolumeService;
import javafxports.android.FXActivity;

public class NativeVolumeServiceAndroid implements NativeVolumeService {

    private static final Logger LOG = Logger.getLogger(NativeVolumeServiceAndroid.class.getName());

    private final AudioManager audioManager;

    private final int maxVolume;
    private int preMuteVolume = 0;
    private int currentVolume = 0;

    public NativeVolumeServiceAndroid() {
        audioManager = (AudioManager) FXActivity.getInstance().getSystemService(Context.AUDIO_SERVICE);
        maxVolume = audioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
    }

    @Override
    public void volumeUp() {
        LOG.info("dispatch volume up event");
        KeyEvent event = new KeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_VOLUME_UP);
        dispatchEvent(event, true, false);
    }

    @Override
    public void volumeDown() {
        LOG.info("dispatch volume down event");
        KeyEvent event = new KeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_VOLUME_DOWN);
        dispatchEvent(event, false, false);
    }

    @Override
    public void mute() {
        LOG.info("dispatch volume mute event");
        KeyEvent event = new KeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_VOLUME_MUTE);
        dispatchEvent(event, false, true);
    }

    private void dispatchEvent(KeyEvent event, boolean up, boolean mute) {

        // hardware key events (amongst others) get caught by the JavaFXPorts engine (or better: the Dalvik impl from Oracle)
        // to circumvent this, we need to do the volume adjustment the hard way: via the AudioManager

        // see: https://developer.android.com/reference/android/media/AudioManager.html
        // see: https://stackoverflow.com/questions/9164347/setting-the-android-system-volume?rq=1

        // reason: 
        // FXActivity registers a FXDalvikEntity, which etends the surface view and passing a key processor 
        // called KeyEventProcessor - this one catches all key events and matches them to JavaFX representations.
        // Unfortunately, we cannot bypass this, so we need the AudioManager

        currentVolume = audioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
        if (mute) {
            if (currentVolume > 0) {
                preMuteVolume = currentVolume;
                audioManager.adjustStreamVolume(AudioManager.STREAM_MUSIC, AudioManager.ADJUST_SAME,
                        AudioManager.FLAG_REMOVE_SOUND_AND_VIBRATE | AudioManager.FLAG_SHOW_UI);
            } else {
                preMuteVolume = 0;
                audioManager.adjustStreamVolume(AudioManager.STREAM_MUSIC, preMuteVolume, AudioManager.FLAG_SHOW_UI);
            }
        } else if (up) {
            audioManager.adjustStreamVolume(AudioManager.STREAM_MUSIC,
                    (currentVolume + 1) <= maxVolume ? AudioManager.ADJUST_RAISE : AudioManager.ADJUST_SAME, AudioManager.FLAG_SHOW_UI);
        } else if (!up) {
            audioManager.adjustStreamVolume(AudioManager.STREAM_MUSIC,
                    (currentVolume - 1) >= 0 ? AudioManager.ADJUST_LOWER : AudioManager.ADJUST_SAME, AudioManager.FLAG_SHOW_UI);
        }
    }
}

volumeService

是一个类变量

然后我在我的

舞台
s
场景
上注册了一个事件处理程序：

@Override
public void start(Stage stage) throws Exception {
    // initiate everything
    scene.addEventFilter(KeyEvent.ANY, this::handleGlobalKeyEvents);
    // do more stuff, if needed
}

最后，方法
handleGlobalKeyEvents
如下所示：

private void handleGlobalKeyEvents(KeyEvent event) {
    // use a more specific key event type like
    // --> KeyEvent.KEY_RELEASED == event.getEventType()
    // --> KeyEvent.KEY_PRESSED == event.getEventType()
    // without it, we would react on both events, thus doing one operation too much
    if (event.getCode().equals(KeyCode.VOLUME_UP) && KeyEvent.KEY_PRESSED == event.getEventType()) {
        if (volumeService != null) {
            volumeService.volumeUp();
            event.consume();
        }
    }
    if (event.getCode().equals(KeyCode.VOLUME_DOWN) && KeyEvent.KEY_PRESSED == event.getEventType()) {
        if (volumeService != null) {
            volumeService.volumeDown();
            event.consume();
        }
    }
}

最后，解决方案尽可能干净，也不会太复杂。只有这样，直到它的工作是有点讨厌

@若泽·佩雷达：如果你想把这个解决方案作为一个魅力下降插件来集成，请随意，但如果你想的话，被提及和通知会很好

问候,，
丹尼尔，哇！多么好的回应啊！只是提供了两个链接，这似乎表明它没有解决，也没有解决，或者什么？来吧这就是我们正在谈论的安卓系统，它是可以解决的看到我的答案了，我会提供关于这个话题的。我明白了。因为你总是不断地回答自己的问题，所以你对可能提供有关该主题的一些信息的链接不感兴趣。问题是：链接只说明问题，没有任何解决方案。我的意思是，我可以让这个问题没有答案，即使我已经找到了答案。而你的“评论”只是一个链接列表。没有别的了。我很抱歉这么说，但这是没有帮助的（考虑到这些链接背后缺乏有价值的信息）。这非常有效。对于一个应该在较低级别修复的问题，这是一个很好的解决方法。
@Override
public void start(Stage stage) throws Exception {
    // initiate everything
    scene.addEventFilter(KeyEvent.ANY, this::handleGlobalKeyEvents);
    // do more stuff, if needed
}

private void handleGlobalKeyEvents(KeyEvent event) {
    // use a more specific key event type like
    // --> KeyEvent.KEY_RELEASED == event.getEventType()
    // --> KeyEvent.KEY_PRESSED == event.getEventType()
    // without it, we would react on both events, thus doing one operation too much
    if (event.getCode().equals(KeyCode.VOLUME_UP) && KeyEvent.KEY_PRESSED == event.getEventType()) {
        if (volumeService != null) {
            volumeService.volumeUp();
            event.consume();
        }
    }
    if (event.getCode().equals(KeyCode.VOLUME_DOWN) && KeyEvent.KEY_PRESSED == event.getEventType()) {
        if (volumeService != null) {
            volumeService.volumeDown();
            event.consume();
        }
    }
}