Trying to catch the Volume onKeyLongPress() not wo

2019-01-20 10:17发布

问题:

I'm trying to get my app to react to a long key press on volume down with the following code:

public boolean onKeyLongPress(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_VOLUME_DOWN) {
        Log.w("myApp", "LONG PRESS");
    }
    return super.onKeyLongPress(keyCode, event);
}

However, it only spams a bunch of onKeyPress() events for volume down, and onKeyLongPress() never gets called. My intention is to leave the volume down and up "short" presses alone, and have my app react differently to the volume long press.
Can anybody point out what I'm missing?

回答1:

You are almost there. You need to detect the same key event in the onKeyPress handler and start tracking it so that the long press can work. Here's the code you need:

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