Android和onSaveInstance和Restore

我有个大问题。我有一个活动，其中我有两个图像视图。在onCreate中，我列出了10张图片。每次我启动此活动时，两个ImageView都会从列表中随机获取图片并显示它们。例如：当我开始活动时，我可以看到汽车和铅笔，当我再次开始活动时，我可以看到大象和书。 这就是我的问题。当我开始活动并封锁我的手机，然后解锁，我会看到其他照片。我想再次调用onCreate。我创造

@Override    
protected void onSaveInstanceState(Bundle savedInstanceState) {   
    super.onSaveInstanceState(savedInstanceState);
}

public void onRestoreInstanceState(Bundle savedInstanceState) {

    if  (savedInstanceState != null) {
        pictureGameLeft.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair().getImageLeft()));
        pictureGameRight.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair().getImageRight()));         
    }   
}

if (savedInstanceState == null) {
    game = new Game();
    game.initGame();
    addElements(result);

    game.getCurrentLevel().nextPair();

    pictureGameLeft.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair()
        .getImageLeft()));
    pictureGameRight.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair()
        .getImageRight()));

    mRedrawHandler.sleep(1000);             
} 
else {
    pictureGameLeft.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair(
        .getImageLeft()));
    pictureGameRight.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair()
        .getImageRight()));
}

图片左侧和右侧是最后显示的图像。 我在onCreate方法之后编写它们。 如何保存上次看到的图片，如果我锁定和解锁手机，我会得到相同的图片。可能是暂停或暂停需要呼叫

if (savedInstanceState == null) {
    game = new Game();
    game.initGame();
    addElements(result);

    game.getCurrentLevel().nextPair();

    pictureGameLeft.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair()
        .getImageLeft()));
    pictureGameRight.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair()
        .getImageRight()));

    mRedrawHandler.sleep(1000);             
} 
else {
    pictureGameLeft.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair(
        .getImageLeft()));
    pictureGameRight.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair()
        .getImageRight()));
}

编辑： 现在：

if (savedInstanceState == null) {
    game = new Game();
    game.initGame();
    addElements(result);

    game.getCurrentLevel().nextPair();

    pictureGameLeft.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair()
        .getImageLeft()));
    pictureGameRight.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair()
        .getImageRight()));

    mRedrawHandler.sleep(1000);             
} 
else {
    pictureGameLeft.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair(
        .getImageLeft()));
    pictureGameRight.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair()
        .getImageRight()));
}

---

但是我得到了NullPointerException。

我会在做出决定的那一刻将当前选择的图片保存到首选项中。

if (savedInstanceState == null) {
    game = new Game();
    game.initGame();
    addElements(result);

    game.getCurrentLevel().nextPair();

    pictureGameLeft.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair()
        .getImageLeft()));
    pictureGameRight.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair()
        .getImageRight()));

    mRedrawHandler.sleep(1000);             
} 
else {
    pictureGameLeft.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair(
        .getImageLeft()));
    pictureGameRight.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair()
        .getImageRight()));
}

这样你就不必去摆弄生命周期方法了

if (savedInstanceState == null) {
    game = new Game();
    game.initGame();
    addElements(result);

    game.getCurrentLevel().nextPair();

    pictureGameLeft.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair()
        .getImageLeft()));
    pictureGameRight.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair()
        .getImageRight()));

    mRedrawHandler.sleep(1000);             
} 
else {
    pictureGameLeft.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair(
        .getImageLeft()));
    pictureGameRight.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair()
        .getImageRight()));
}

决定何时从偏好中选择或创建新的（随机）选择是很容易的。检查一下

if (savedInstanceState == null) {
    game = new Game();
    game.initGame();
    addElements(result);

    game.getCurrentLevel().nextPair();

    pictureGameLeft.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair()
        .getImageLeft()));
    pictureGameRight.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair()
        .getImageRight()));

    mRedrawHandler.sleep(1000);             
} 
else {
    pictureGameLeft.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair(
        .getImageLeft()));
    pictureGameRight.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair()
        .getImageRight()));
}

savedInstanceState

的

if (savedInstanceState == null) {
    game = new Game();
    game.initGame();
    addElements(result);

    game.getCurrentLevel().nextPair();

    pictureGameLeft.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair()
        .getImageLeft()));
    pictureGameRight.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair()
        .getImageRight()));

    mRedrawHandler.sleep(1000);             
} 
else {
    pictureGameLeft.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair(
        .getImageLeft()));
    pictureGameRight.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair()
        .getImageRight()));
}

---

是空的。如果是，这是第一个电话。随后的重新打开有一个非空值

现在我得到java.lang.RuntimeException:无法暂停活动

if (savedInstanceState == null) {
    game = new Game();
    game.initGame();
    addElements(result);

    game.getCurrentLevel().nextPair();

    pictureGameLeft.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair()
        .getImageLeft()));
    pictureGameRight.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair()
        .getImageRight()));

    mRedrawHandler.sleep(1000);             
} 
else {
    pictureGameLeft.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair(
        .getImageLeft()));
    pictureGameRight.setImageResource(shapesPictures.get(game.getCurrentLevel().getCurrentPair()
        .getImageRight()));
}