动画布局刷新交叉渐变

Question

Android新手在这里，我有一个函数在我的主活动刷新天气数据;它通过在两个片段中调用函数来实现这一点，这两个片段从web API中提取新数据。当你点击刷新按钮/改变位置时，我想要两个片段布局交叉褪色，我似乎无法让animateLayoutChanges ="true"去做我所期望的(当视图设置为视图时交叉褪色)。离开并回到View.VISIBLE)。我做事的顺序不对吗?

我代码:

 public void refreshCity(){
        //This block sets references to the fragment layouts and sets them to GONE
        RelativeLayout wfLayout =  (RelativeLayout)findViewById(R.id.fragment_weather);
        LinearLayout ffLayout = (LinearLayout)findViewById(R.id.fragment_forecast);
        wfLayout.setVisibility(View.GONE);
        ffLayout.setVisibility(View.GONE);
        //This block gets references to the fragments themselves and calls the
        //changeCity function in each with the current city - this block definitely works
        FragmentManager fm = getSupportFragmentManager();
        WeatherFragment wf = (WeatherFragment)fm
                .findFragmentByTag(makeFragmentName(R.id.pager, 0));
        ForecastFragment ff = (ForecastFragment)fm
                .findFragmentByTag(makeFragmentName(R.id.pager, 1));
        CityPreference cf = new CityPreference(this);
        wf.changeCity(cf.getCity());
        ff.changeCity(cf.getCity());
        //I then set the layouts back to visible
        wfLayout.setVisibility(View.VISIBLE);
        ffLayout.setVisibility(View.VISIBLE);
    }

片段刷新并显示数据，但没有淡出。animateLayoutChanges在两个片段布局中都被设置为true，是否有一些保护来引用它们所引用的片段之外的布局?任何帮助都非常感激!

Answer 1

所以我想出了解决方案;我取消了在xml文件中使用animateLayoutChanges，并添加了一个ViewPropertyAnimator到每个片段的changeCity()函数(用于更新视图中显示的数据)。

public void changeCity(final String city){
        final LinearLayout layout = (LinearLayout)getActivity()
                .findViewById(R.id.fragment_forecast);
        layout.animate().setDuration(600);
        layout.animate().alpha(0);
        Runnable endAction = new Runnable() {
            @Override
            public void run() {
                updateForecastData(city);
                layout.animate().alpha(1);
            }
        };
        layout.animate().withEndAction(endAction);
    }

更新数据和淡出视图的调用我放置在一个runnable中，这个runnable是由ViewPropertyAnimator函数withEndAction(Runnable runnable)调用的，它只在当前动画完成时运行，所以视图淡出-> endAction runnable运行，数据更新->视图淡出。