Question

这似乎很简单，应该看起来像：

private long DOUBLE_CLICK_DELAY = 150;
private long lastButtonClick = // oldValue
private long currentButtonClick = System.currentTimeMillis();
...
if (currentButtonClick - lastButtonClick < DOUBLE_CLICK_DELAY ) // bla-bla

但是我无法在BroadcastReceiver中保存先前点击的旧值。我应该将它保存在临时数据库中吗？（没有使用任何活动）

public class RemoteControlReceiver extends BroadcastReceiver {

@Override
  public void onReceive(Context context, Intent intent) {
    if (Intent.ACTION_MEDIA_BUTTON.equals(intent.getAction())) {
      if (/* DOUBLE_CLICK */){
        Toast.makeText(context, "Tra-la-la!", 100).show();      
      }
    }
  } 

}

Answer 1

好吧，多亏了@gianpi，它正在使用SharedPreferences。但在这种情况下，不确定良好的读/写速度。无论如何，如果有任何人对此感兴趣：

@Override
  public void onReceive(Context context, Intent intent) {
    if (Intent.ACTION_MEDIA_BUTTON.equals(intent.getAction())) {
      KeyEvent keyEvent = (KeyEvent) intent.getParcelableExtra(Intent.EXTRA_KEY_EVENT);
        if (keyEvent != null) {
            if (keyEvent.getAction() == KeyEvent.ACTION_UP) {
                SharedPreferences settings = context.getSharedPreferences(PREFS_NAME, 0);
                long last = settings.getLong("last", 0);
                long delta = System.currentTimeMillis() - last;
                if (delta < DOUBLE_CLICK_DELAY) {             
                  context.startService(new Intent(context, MyService.class));
                }
                SharedPreferences.Editor editor = settings.edit();
                editor.putLong("last", System.currentTimeMillis());
                editor.commit();
            }
        }
     }
  }

Answer 2

也许这篇文章已经有点老了，但今天我遇到了同样的问题，我找到了一个更好（或至少更“优雅”）的解决方案，而不是使用共享偏好。

在MainActivity中将全局变量声明为static：

static final long DOUBLE_CLICK_DELAY = 150;
static long lastButtonClick = 0; // oldValue
static long currentButtonClick = System.currentTimeMillis();

现在，从RemoteControlReceiver类中执行以下操作：

@Override
public void onReceive(Context context, Intent intent) {
    String intentAction = intent.getAction();
    if (!Intent.ACTION_MEDIA_BUTTON.equals(intentAction)) {
        return;
    }
    KeyEvent event = (KeyEvent)intent.getParcelableExtra(Intent.EXTRA_KEY_EVENT);
    if (event == null) {
        return;
    }
    int action = event.getAction();
    if (action == KeyEvent.ACTION_DOWN) {
        // Do something for action down
    }
    else if(action == KeyEvent.ACTION_UP){
        MainActivity.lastPressTime = MainActivity.newPressTime;
        MainActivity.newPressTime = System.currentTimeMillis();
        long delta = MainActivity.newPressTime - MainActivity.lastPressTime;

        // Case for double click
        if(delta < MainActivity.DOUBLE_CLICK_DELAY){
            // Do something for double click
        }
    }
}

如何检测MEDIA_BUTTON双击？

2 个答案: