有时打电话initLoader后没有得到onCreateLoader回调 [英] Sometimes don't get onCreateLoader callback after calling initLoader
问题描述
我以加载该活动将显示数据被创建时调用initLoader的活动。通常情况下，这工作正常。我必须设置看，一切发生的顺序断点。首先，我打电话initLoader，然后我得到了OnCreateLoader回调，那么回调OnLoadFinished，那么一切都很好。
I have an activity that calls initLoader when it is created in order to load the data that the activity will display. Normally, this works fine. I have breakpoints set to see the order that everything happens. First I call initLoader, then I get the OnCreateLoader callback, then the OnLoadFinished callback, then everything is great.
不过，我注意到，如果我改变了对我的Android的方向，我没有得到OnCreateLoader回调或回调OnLoadFinished，导致没有在网页上显示的数据。我仍然得到我的电话initLoader断点，所以我知道正在发生的事情，但我没有得到一个错误，我无法找到任何文件，解释我为什么不打电话initLoader后得到一个回调。
However, I noticed that if I changed the orientation on my Android that I don't get the OnCreateLoader callback or the OnLoadFinished callback, resulting in no data displayed on the page. I still get my breakpoint on the initLoader call so I know that is happening, but I don't get an error and I can't find any documentation explaining why I wouldn't get a callback after calling initLoader.
有趣的是，我得到的回调，如果我回到原来的方向。
Interestingly, I do get the callbacks if I return to the original orientation.
因此，要总结：
我开始在纵向活动
- 我叫initLoader
- 我得到onCreateLoader和onLoadFinished回调
然后我更改为横向
- 我叫initLoader
- 没有onCreateLoader或onLoadFinished回调
我改回为纵向
- 我叫initLoader
- 我得到onCreateLoader和onLoadFinished回调
同样，如果我开始在横向模式下的活动我得到的回调。然后，如果我切换到肖像，我不知道。然后，如果我切换到横向，我再次得到了回调。
Similarly, if I start the activity in landscape mode I get the callbacks. Then, if I switch to portrait, I don't. Then, if I switch back to landscape I get the callbacks again.
有没有人有任何想法，这是怎么回事？
Does anyone have any idea what's going on?
推荐答案
我们已经看到了这个同样的问题在ViewPager片段。看来该装载机没有正确再次激活时恢复的片段。事实上，当片段被暂停，我们CursorLoader不再得到ContentObserver回调，因为我期望的那样。
We've seen this same problem with Fragments in a ViewPager. It appears that the loaders are not properly activated again when a fragment is resumed. In fact, when the fragment is paused, our CursorLoader no longer gets ContentObserver callbacks as I would expect.
我们的解决方法已经调用restartLoader（），它转储previous内容并重新加载数据。这将对作为destroyLoader相同的净影响（）; initLoader（），但它会更有效。
Our workaround has been to call restartLoader() which dumps the previous contents and reloads the data. This would have the same net affect as destroyLoader(); initLoader(), but it will be more efficient.
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