Question

我需要使用音量按钮来控制应用程序中的变量参数。我按Activity.onKeyDown时会在按下按钮时收到通知，但媒体音量也会增加当我按下音量键时，Android正在执行以下操作：

增加媒体/铃声音量
将活动传递给我的申请

有没有办法避免增加系统音量并仅为我的应用程序使用音量键？

Answer 1

您需要捕获所有操作：

@Override
public boolean dispatchKeyEvent(KeyEvent event) {
    int action = event.getAction();
    int keyCode = event.getKeyCode();
        switch (keyCode) {
        case KeyEvent.KEYCODE_VOLUME_UP:
            if (action == KeyEvent.ACTION_DOWN) {
                //TODO
            }
            return true;
        case KeyEvent.KEYCODE_VOLUME_DOWN:
            if (action == KeyEvent.ACTION_DOWN) {
                //TODO
            }
            return true;
        default:
            return super.dispatchKeyEvent(event);
        }
    }

Answer 2

下一个会更好，因为KeyEvent.KEYCODE_VOLUME_UP的长按不能在上一个答案中正常工作。

@Override
public boolean dispatchKeyEvent(KeyEvent event) {
    int action = event.getAction();
    int keyCode = event.getKeyCode();
    switch (keyCode) {
        case KeyEvent.KEYCODE_VOLUME_UP:
            if (action == KeyEvent.ACTION_DOWN) {
                //TODO
            }
            return true;
        case KeyEvent.KEYCODE_VOLUME_DOWN:
            if (action == KeyEvent.ACTION_DOWN) {
                //TODO
            }
            return true;
        default:
            return super.dispatchKeyEvent(event);
    }
}

Answer 3

只是为了完成之前的答案，如果你想要长按支持，你应该检查密钥关闭的时间：

event.getEventTime() - event.getDownTime() > ViewConfiguration.getLongPressTimeout()

最后代码如下所示：

    @Override
public boolean dispatchKeyEvent(KeyEvent event) {
    int action = event.getAction();
    int keyCode = event.getKeyCode();
    switch (keyCode) {
        case KeyEvent.KEYCODE_VOLUME_UP:
            if (action == KeyEvent.ACTION_UP) {
                if (event.getEventTime() - event.getDownTime() > ViewConfiguration.getLongPressTimeout()) {
                    //TODO long click action
                } else {
                    //TODO click action
                }
            }
            return true;
        case KeyEvent.KEYCODE_VOLUME_DOWN:
            if (action == KeyEvent.ACTION_UP) {
                if (event.getEventTime() - event.getDownTime() > ViewConfiguration.getLongPressTimeout()) {
                    //TODO long click action
                } else {
                    //TODO click action
                }
            }
            return true;
        default:
            return super.dispatchKeyEvent(event);
    }
}

Answer 4

我之前用过这段代码来听取音量按钮。

  @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if ((keyCode == KeyEvent.KEYCODE_VOLUME_DOWN)){
            //Do something
        }
        return true;
    }

Answer 5

碎片中的卷按钮用法

如果您希望在绑定Activity的片段中实现此功能，可以使用as：

注意：fragment_words只是一个仲裁使用的布局名称

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.fragment_words, container, false);
rootView.requestFocus();
    rootView.setOnKeyListener(new View.OnKeyListener() {
            @Override
            public boolean onKey(View v, int keyCode, KeyEvent event) {

                if( keyCode == KeyEvent.KEYCOD_VOLUME_DOWN ) {

                    //TODO SOMETHING
                    return true;
                } else {
                    return false;
                }
            }
        });}

Answer 6

具有双击操作的音量

public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_VOLUME_DOWN) {
        i++;
        Handler handler= new Handler();
        Runnable runnable=new Runnable() {
            @Override
            public void run() {
                i=0;
            }
        };
        if(i==1){
            Toast.makeText(getApplicationContext(),"single click",Toast.LENGTH_SHORT).show();
            handler.postDelayed(runnable,400);
        }
        else if(i==2){
            Vibrator vb = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
            vb.vibrate(100);
        }

        return true;
    }
    if (keyCode == KeyEvent.KEYCODE_VOLUME_UP) {
        return true;
    } else {
        return super.onKeyDown(keyCode, event);
    }
}

Answer 7

我在AB快门（蓝牙）始终启动音量时遇到问题，而我想将蓝牙键盘事件用于其他功能。但是我仍然希望从设备的音量调高按钮调高音量。我发现的解决方案是处理短暂事件，并且仅在按住设备按钮一秒钟以上时才允许更改音量。看到代码：

boolean bVolumeUpKeyDown = false;
long StartDownMS = 0;

@Override
public boolean dispatchKeyEvent(KeyEvent event) {
    int action = event.getAction();
    int keyCode = event.getKeyCode();
    switch (keyCode) {
        case KeyEvent.KEYCODE_VOLUME_UP:
            if (action == KeyEvent.ACTION_UP) {
                // my handling of keyevent
                return true;
              }
              else if  (action == KeyEvent.ACTION_DOWN) {
                  if(bVolumeUpKeyDown == false) {
                      bVolumeUpKeyDown = true;
                      StartDownMS = System.currentTimeMillis();
                  }
                  else if(System.currentTimeMillis() - StartDownMS > 1000)
                      return super.dispatchKeyEvent(event); // normal volume up handling
            }
            return true;

       case KeyEvent.KEYCODE_ENTER:
           if (action == KeyEvent.ACTION_UP) {
           //my handling of second ab shutter button
                }
            return true;

       default:
            return super.dispatchKeyEvent(event);
    }
}

Android - 我的应用程序中使用的音量按钮

7 个答案:

碎片中的卷按钮用法