如何使用PHP解析此XML？(How to parse this XML using PHP?)

 你问： 
 
 
 
 这个可以吗？ 
 
 
 很大程度上，是的。 
 
 更准确地说，这取决于您的需求/意图。 如果您需要继续运行以使您的应用程序正常运行（例如，您可能正在转换并保存一些图像），那么您肯定需要一个强大的参考，以便它完成）。 
 
 但如果您不需要继续执行，那么您将使用weakSelf模式。 例如，假设您在视图控制器中有一系列调度任务，这些任务仅用于以后触发UI更新。 在这种情况下，如果视图控制器被解除，您可能不需要运行这些块，并且您当然不希望它挂起到视图控制器以获取已被解雇的视图。 （您甚至可能希望在取消视图控制器时取消这些已分派的项目，但这是另一个主题。） 
 
 底线，这取决于你的意图。 

You ask:
 
 
 
Is this okay?
 
 
Largely, yes.
 
More accurately, it depends upon your needs/intent. If you need this to continue to run for your app to function properly (e.g. maybe you're converting and saving some images), then you definitely want a strong reference so that it finishes). 
 
But if you don't need to continue to execute, then you'd use weakSelf pattern. For example, imagine you had a series of dispatched tasks in a view controller that were there solely to later trigger UI updates. In that case, if the view controller was dismissed, you might not need these blocks to run, and you certainly wouldn't want it to hang on to the view controller for a view that was long since dismissed. (You might even want to cancel those dispatched items when the view controller was dismissed, but that's another topic.)
 
Bottom line, it depends upon your intent.