问访问其他java类的片段

EN

- If you are not aware, Creating an object by calling new MyClass() takes up resources and also the object creation process is time consuming. So if you call them inside onResume() or onStart() method those objects will be created when the fragment move from visible state to focused(foreground - onResume() is called) and from background to visible(onStart() is called) state .
- This happens often when another application comes into focus(which causes the fragment to call onResume() or onStart() when your application comes into foreground) or when our application moves from background to visible state(onStart() is called). So object is created everytime this happens.
- But on the other hand if you create it inside onCreate() or lifecycle methods above it the objects will be created only when the fragment is destroyed and recreated.
- Also if you want to call methods from the class you have instantiated by above method you can call it from any lifecycle  method below the onCreate() like in onStart() (if you wanted to show results before the user uses your fragment) or in onResume() (if you wanted to show results after the user sees it) it is upto you to do this.
- Also in my example above i have called retrieveData() method from onStart() and i have wrote that method from outside the lifecycle methods. it is just for an example. You can do like that. But you have to call those methods inside the lifecycle methods according to your needs. 
- Finally here is a link to learn more about the lifecycle methods of the Fragment. [Learn About Fragment LifeCycle](https://developer.xamarin.com/guides/android/platform_features/fragments/part_1_-_creating_a_fragment/)