android - 实现 QuickActions UI 模式

Question

我一直在尝试在我的应用程序中实现 QuickActions UI 模式。我发现了几个添加了 QuickAction 的库，但它们都有一个共同点——QuickAction 弹出窗口总是在 Activity 中实现。

作为我的应用程序的一部分，我有一个可滑动的 View ，其中包含 2 个 ListFragments，这使我可以在两者之间快速切换。但是，每当我尝试实现此 UI 模式时，都会在调用 QuickAction.show 时导致 NullPointerExceptions。到目前为止，我已经尝试过 NewQuickActions 以及 Qberticus 的 LikeQuickActions。两者都有完全相同的问题。我的问题是，是否存在阻止 PopupWindow 锚定到 fragment 内的 ListItem 的基本限制？或者我只是做错了什么。作为引用，这是我使用的代码。

public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                                  Bundle savedInstanceState) {

    View v = inflater.inflate(R.layout.fridge_food_tab, container,false);
    listView = (ListView) v.findViewById(R.id.fridge_food_list);

    getActivity().getSupportLoaderManager().initLoader(FRIDGE_FOOD_LOADER, null, this);

    adapter = new FridgeCursorAdapter(getActivity().getApplicationContext(), 
                  R.layout.fridge_list_layout, null, uiBindFrom, uiBindTo, 
                  CursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER);

    final QuickAction qa = new QuickAction(getActivity());

    ActionItem item = new ActionItem(getResources()
                          .getDrawable(android.R.drawable.ic_input_add));

    qa.addActionItem(item); //<-- Line 51

    listView.setOnItemClickListener(new OnItemClickListener() {

        public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
            qa.show(arg1);
        }
    });

listView.setAdapter(adapter);
return v;
}

这是发生的异常

10-06 18:40:53.617: E/AndroidRuntime(17832): FATAL EXCEPTION: main
10-06 18:40:53.617: E/AndroidRuntime(17832): java.lang.NullPointerException
10-06 18:40:53.617: E/AndroidRuntime(17832): at net.londatiga.android.QuickAction.addActionItem(QuickAction.java:151)
10-06 18:40:53.617: E/AndroidRuntime(17832): at app.le.sauce.fridge.FoodTabFragment.onCreateView(FoodTabFragment.java:51)
10-06 18:40:53.617: E/AndroidRuntime(17832): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:871)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1083)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:635)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1431)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:431)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.support.v4.app.FragmentStatePagerAdapter.finishUpdate(FragmentStatePagerAdapter.java:160)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.support.v4.view.ViewPager.populate(ViewPager.java:895)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.support.v4.view.ViewPager.populate(ViewPager.java:772)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1234)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.view.View.measure(View.java:15172)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4814)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1390)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.widget.LinearLayout.measureVertical(LinearLayout.java:681)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.widget.LinearLayout.onMeasure(LinearLayout.java:574)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.view.View.measure(View.java:15172)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4814)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.view.View.measure(View.java:15172)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.widget.LinearLayout.measureVertical(LinearLayout.java:833)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.widget.LinearLayout.onMeasure(LinearLayout.java:574)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.view.View.measure(View.java:15172)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4814)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2150)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.view.View.measure(View.java:15172)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1848)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1100)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1273)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:998)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4212)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:725)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.view.Choreographer.doCallbacks(Choreographer.java:555)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.view.Choreographer.doFrame(Choreographer.java:525)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:711)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.os.Handler.handleCallback(Handler.java:615)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.os.Handler.dispatchMessage(Handler.java:92)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.os.Looper.loop(Looper.java:137)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at android.app.ActivityThread.main(ActivityThread.java:4931)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at java.lang.reflect.Method.invokeNative(Native Method)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at java.lang.reflect.Method.invoke(Method.java:511)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:558)
10-06 18:40:53.617: E/AndroidRuntime(17832):    at dalvik.system.NativeStart.main(Native Method)

Answer 1

很遗憾，这可能不是您正在寻找的答案，因为它更像是一种解释而非解决方案。

在第 51 行，您调用了 qa.addActionItem(item);。这导致 addActionItem(ActionItem action) of QuickAction.java .所以，我看了看；您的崩溃发生在该文件的第 151 行，即:

public void addActionItem(ActionItem action) {
    mActionItemList.add(action);

    String title    = action.getTitle();
    Drawable icon   = action.getIcon();

    View container  = (View) inflater.inflate(R.layout.action_item, null);

    ImageView img   = (ImageView) container.findViewById(R.id.iv_icon);
    TextView text   = (TextView) container.findViewById(R.id.tv_title);

    if (icon != null) { 
        img.setImageDrawable(icon); // This line here.
    } else {
        img.setVisibility(View.GONE);
    }

    // ...

}

现在，显然，在这一行中，icon 不能为 null。所以，看起来 img 是。从那里，我们可以得出结论，container 不包含 ID 为 iv_icon 的元素。但是，当我查看 action_item XML 文件时，它确实存在。

所以，我有几点建议:

1. 验证没有第二个 action_item.xml 文件可能正在读取(在您的图书馆、它的图书馆或任何其他图书馆中)。
2. 清理 QuickAction 项目，让它构建，然后清理你的项目，让它构建，然后运行它。
3. 尝试使用库代码。 (测试 null，尝试弄清楚什么被夸大了，什么没有。)
4. 如果一切都失败了，请联系库创建者。他的电子邮件可以在 the library homepage 上找到.