Firebase和react-native集成(Firebase and react-native integration)

 我相信我通过重新审视重新创建活动找到了答案。 
 
 另外，根据运行时更改的文档 ： 
 
 您的应用程序应该能够在不丢失用户数据或状态的情况下随时重新启动，以便处理诸如配置更改之类的事件，或者当用户收到来电时，然后在您的申请过程之后很久就返回到您的应用程序销毁。 要了解如何恢复活动状态，请阅读活动生命周期。 
 
 因此，我现在将研究如何使用Bundle在Activity娱乐上保存和恢复信息。 
 
 此外，我可能需要暂停当前的SomeClass实例，并在Activity恢复时创建一个新实例。 然而这是相当棘手的，因为我在SomeClass中运行了一个for循环，所以没有线索如何解决...仍然，我认为在SomeClass内部的方法内调用getSupportActionBar（）有点奇怪到最后（并销毁）Activity而不是新创建的Activity，但这是如何编译的呢？ 
 
 更新我最终选择通过将这些存储在Activity类范围的静态变量中来跟踪当前的ActionBar和Window。 我通过在onCreate方法中添加这些行来重新创建这些变量： 
 
@Override
protected void onCreate(Bundle savedInstanceState) {
    (..)
    storedActionBar = actionBar; //PETER: added to be able to access the new ActionBar upon Activiy Recreate (e.g. orientation change)
    storedWindow = getWindow(); // for the KEEP_SCREEN_ON flag

I believe I found the answer by looking more into Recreating an Activity.
 
Also, according to the documentation on Runtime Changes:
 
Your application should be able to restart at any time without loss of user data or state in order to handle events such as configuration changes or when the user receives an incoming phone call and then returns to your application much later after your application process may have been destroyed. To learn how you can restore your activity state, read about the Activity lifecycle.
 
Therefore I will now look into how to use the Bundle to save and restore information upon Activity recreation. 
 
Moreover, I probably need to pause my current SomeClass instance, and create a new one upon Activity restore. This is however rather tricky, as I have a for loop running inside the SomeClass, so no clues yet how to solve that... Still, I think it is a bit weird that the getSupportActionBar() call inside the method inside the SomeClass refers to the last (and destroyed) Activity rather then the newly created Activity, but this is how it is compiled apparently?
 
Update I finally chose to keep track of the current ActionBar and Window by storing these in Activity class wide static variables. I update these variables upon Recreation by adding these lines in the onCreate method:
 
@Override
protected void onCreate(Bundle savedInstanceState) {
    (..)
    storedActionBar = actionBar; //PETER: added to be able to access the new ActionBar upon Activiy Recreate (e.g. orientation change)
    storedWindow = getWindow(); // for the KEEP_SCREEN_ON flag