Android 程序是否是在前端運行

/**
 * 程序是否在前臺運行
 *
 * @return
 */
public boolean isAppOnForeground() {
    ActivityManager activityManager = (ActivityManager) getApplicationContext().getSystemService(Context.ACTIVITY_SERVICE);
    String packageName = getApplicationContext().getPackageName();
    List<ActivityManager.RunningAppProcessInfo> appProcesses = activityManager
            .getRunningAppProcesses();
    if (appProcesses == null)
        return false;
    for (ActivityManager.RunningAppProcessInfo appProcess : appProcesses) {
        // The name of the process that this object is associated with.
        if (appProcess.processName.equals(packageName)
                && appProcess.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND) {
            return true;
        }
    }
    return false;
}