Android:如何知道设备何时锁定和解锁

Question

我正在开发一个具有后台进程的应用程序，我的应用程序中的一些功能只有在用户打开屏幕并解锁“锁定屏幕”时才能使用。有针对SCREEN_ON、SCREEN_OFF 和USER_PRESENT 的操作。

我在 SCREEN_OFF 事件上重置了一个标志，并将其设置在 USER_PRESENT 事件上，这工作正常，但这里我有另一个问题；在设置中有一个选项“使用电源按钮立即锁定”，如果取消选中，设备将在 sleep 5 秒后才会锁定。

现在，如果用户关闭屏幕并在 5 秒内打开它，将调用 SCREEN_OFF 事件而永远不会调用 USER_PRESENT 事件。

是否有针对 USER_NOT_PRESENT 或 DEVICE_LOCKED 的任何操作，以便我可以在那里重置我的标志？

注意:如果我知道设置"lock_screen_lock_after_timeout" 和"power_button_instantly_locks"，我可以变通。但是我可以获得如下“lock_screen_lock_after_timeout”设置但不知道如何获得“power_button_instantly_locks”

ContentResolver mResolver = ctx.getContentResolver();
long timeout = Settings.Secure.getLong(mResolver, "lock_screen_lock_after_timeout", 0);

谢谢。任何其他方法也应受到赞赏。

Answer 1

使用反射获取power_button_instantly_locks的设置值。请看下面的代码:

/**
  *This function is used to detect the system setting: Power button instantly locks. To see whether this setting is enabled or not.
  * @return true if Power button instantly locks is enabled, otherwise, false.
  */

private boolean isPowerButtonInstantlyLocksOn(){
    String LOCK_PATTERN_UTILS="com.android.internal.widget.LockPatternUtils";
    String POWER_BUTTON_INSTANTLY_LOCKS="getPowerButtonInstantlyLocks";
    boolean isPowerButtonInstantlyLocks=false;
    try{
        Class<?> lockPatternUtilsClass=Class.forName(LOCK_PATTERN_UTILS);
        Object lockPatternUtils=lockPatternUtilsClass.getConstructor(Context.class).newInstance(this);

        // According to the source code of Android 6, the function getPowerButtonInstantlyLocks is declared with a parameter "int userId"
        if (Build.VERSION.SDK_INT>=Build.VERSION_CODES.M){
            Method method = lockPatternUtilsClass.getMethod(POWER_BUTTON_INSTANTLY_LOCKS,new Class[]{int.class});
            isPowerButtonInstantlyLocks=Boolean.valueOf(String.valueOf(method.invoke(lockPatternUtils,userID())));
        }else {
            Method method = lockPatternUtilsClass.getMethod(POWER_BUTTON_INSTANTLY_LOCKS);
            isPowerButtonInstantlyLocks=Boolean.valueOf(String.valueOf(method.invoke(lockPatternUtils,null)));
        }
    }catch (Exception e){
        Crashlytics.logException(e);
        e.printStackTrace();
    }
    return isPowerButtonInstantlyLocks;
}

/**
 * This function is used to check the current userID
 * @return
 */
private int userID(){
    // myUserId is a hidden function in Class UserHandle that we want to use to return the current user ID
    String MY_USER_ID="myUserId";
    int userId=0;

    try{
        // android.os.Process.myUserHandle() is called to get a UserHandle instance
        // myUserHandle requires API 17, but it is OK, cause the function userID() will only be called at API 23
        if (Build.VERSION.SDK_INT>Build.VERSION_CODES.JELLY_BEAN){
            UserHandle userHandle=android.os.Process.myUserHandle();
            Method method = UserHandle.class.getMethod(MY_USER_ID);
            userId=Integer.valueOf(String.valueOf(method.invoke(userHandle,null)));
        }
    }catch (Exception e){
        Crashlytics.logException(e);
        e.printStackTrace();
    }

    return userId;
}