ViewPropertyAnimator意外循环

Question

我正在尝试设置一组按钮的动画，使它们在单击时按顺序消失，然后根据单击的按钮执行操作。该操作被分配给在动画结束时触发的动画侦听器。这可以很好地工作。

问题是，当活动恢复时，我希望按钮按顺序重新出现。由于某些原因，即使在将动画设置为空之后，分配给动画侦听器的操作也会重新触发。我遗漏了什么？

public class MainMenu extends ActionBarActivity {

private MenuItemBuilder menuItemBuilder;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main_menu);

    init();
}

private void init() {
    menuItemBuilder = new MenuItemBuilder(this);
}

@Override
protected void onResume() {
    super.onResume();

    if (menuItemBuilder != null) {
        menuItemBuilder.animateAllViewsEnter();
    }
}

下面是菜单构建器。我有三个菜单项:加载数据库，价目表和关于。这个类管理所有的动画。

public MenuItemBuilder(Context context) {
    this.context = context;

    init();
}

private void init() {
    initLoadDatabase();
    initPriceList();
    initAbout();
}

private View getViewFromId(int res) {
    return ((Activity) context).findViewById(res);
}

private ImageButton getImageButtonFromId(int res) {
    return (ImageButton) ((Activity) context).findViewById(res);
}

private void initLoadDatabase() {
    final ImageButton button = getImageButtonFromId(R.id.imageLoadDatabase);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            animateAllViewsExit(ButtonType.LOAD_DATABASE);
        }
    });
}

private void initPriceList() {
    final ImageButton button = getImageButtonFromId(R.id.imagePriceList);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            animateAllViewsExit(ButtonType.PRICE_LIST);
        }
    });
}

private void initAbout() {
    final ImageButton button = getImageButtonFromId(R.id.imageAbout);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            animateAllViewsExit(ButtonType.ABOUT);
        }
    });
}

private List<View> getAnimatedViews() {
    List<View> viewList = new ArrayList<>();
    viewList.add(getViewFromId(R.id.imageLoadDatabase));
    viewList.add(getViewFromId(R.id.priceListContainer));
    viewList.add(getViewFromId(R.id.imageAbout));

    return viewList;
}

public void animateAllViewsEnter() {
    List<View> viewList = getAnimatedViews();
    for (int i = 0; i < viewList.size(); i++) {
        View view = viewList.get(i);
        view.animate()
                .setStartDelay((viewList.size() - i) * 250)
                .alpha(1.0f);
    }
}

private void animateAllViewsExit(ButtonType buttonType) {
    List<View> viewList = getAnimatedViews();
    for (int i = 0; i < viewList.size(); i++) {
        View view = viewList.get(i);
        ViewPropertyAnimator animator = view.animate()
                .setStartDelay(i * 250)
                .alpha(0.0f);

        if (i == viewList.size() - 1) {
            lastAnimation = animator;
        }
    }

    setAnimationAction(buttonType);
}

private void setAnimationAction(final ButtonType buttonType) {
    if (lastAnimation != null) {
        lastAnimation.setListener(new Animator.AnimatorListener() {
            @Override
            public void onAnimationStart(Animator animation) {
            }

            @Override
            public void onAnimationEnd(Animator animation) {
                performAction(buttonType);
                lastAnimation = null;
            }

            @Override
            public void onAnimationCancel(Animator animation) {
            }

            @Override
            public void onAnimationRepeat(Animator animation) {
            }
        });
    }
}

private void performAction(ButtonType buttonType) {
    switch (buttonType) {
        case LOAD_DATABASE:
            // TODO to be done
            break;
        case PRICE_LIST:
            context.startActivity(new Intent(context, PriceList.class));
            break;
        case ABOUT:
            context.startActivity(new Intent(context, About.class));
            break;
    }
}

private enum ButtonType {
    LOAD_DATABASE,
    PRICE_LIST,
    ABOUT
}

Answer 1

通过将侦听器设置为进入和退出动画，修复了此问题。

public void animateAllViewsEnter() {
    List<View> viewList = getAnimatedViews();
    for (int i = 0; i < viewList.size(); i++) {
        View view = viewList.get(i);
        view.animate()
                .setStartDelay((viewList.size() - i) * 250)
                .alpha(1.0f)
                .setListener(null);
    }
}

private void animateAllViewsExit(ButtonType buttonType) {
    List<View> viewList = getAnimatedViews();
    for (int i = 0; i < viewList.size(); i++) {
        viewList.get(i).animate()
                .setStartDelay(i * 250)
                .alpha(0.0f)
                .setListener(getAnimatorListener(i == viewList.size() - 1, buttonType));
    }
}