安卓paging库自定义datasource时千万不要在loadInitial()中异步设置返回数据

如题.

我们可能之前习惯通过rxjava的方式请求网络数据了, 并在在onNext()方法中处理返回结果.
但是千万不要在自定的paging库中的几种DataSource类中这么做.
尤其是loadInitial(), 这并不单单是性能的问题, 而是可能无法正常显示得到的数据.

这里有一篇中文的流程分析, 里面也提到了这个问题, 但是我没看明白他说的原因.
https://ankko.github.io/2018/09/12/Android%E7%BB%84%E4%BB%B6Paging%E7%9A%84%E4%BD%BF%E7%94%A8%E5%8F%8A%E5%8E%9F%E7%90%86/

这里还有一篇英文的使用示例, 里面也提到了这个问题
https://medium.com/@Ahmed.AbdElmeged/android-paging-library-with-rxjava-and-rest-api-e5c229fd70ba

You maybe wonder why i don’t use one of Rx most powerful features which specify the threads i want to work in or observe on. I already try this but it give strange behavior after some analysis i realize that the load methods called on background thread provided by Paging. The problem is you get the data on thread and load methods called on another thread.

WTF!