Android : Accessing container activity object from

问题:

I am building a tab interface using Action bar and fragment. I would need assistance in sending data from container activity to the fragment.

To elaborate, I have job object in container activty. And I have created few tabs based on the information in job object (like company details, experience details etc). I need to pass the job object to these fragments so that it can display respective information.

I have created container activity and tab fragments. I would need an example on how to pass the object across them. I cannot use intent.putExtra. Can I access parent container's object from fragment?

Any help shall be appreciated.

Thanks.

回答1:

Make the method in your activity, e.g getJob that will return the Job object and its information

MyActivity extends Activity{
Job mJob;

public Job getJob(){
   return this.mJob;
 }
}

then in your Fragment you do this:

MyFragment extends Fragment{

@Override
public void onActivityCreated(){
  super.onActivityCreated();
  ((MyActivity)this.getActivity()).getJob();
 }
}

use getActivity and the method getJob(); to get the object

回答2:

There are multiple ways of achieving this.

1. Make a static variable to hold your data and access that data from inside the fragments - this is the most fast but it creates bad design patterns if used improperly.
2. A way of Fragment-to-Fragment communication possible through the parent Activity is posted here: http://developer.android.com/training/basics/fragments/communicating.html You can use the sample code to just do a Activity - Fragment data send.
3. The top voted answer here: Accessing instance of the parent activity? mentions a way to avoid using static data (1.) and contains source code examples using ActivityGroup

"If you need access to some values in your First activity without making a static reference to it, you could consider putting your activities in an ActivityGroup."

What you choose is your preference, these are just a few options!

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Edit: I'm not sure if number 3 will work with fragments since I haven't tested a method similar to it, the example is Activity - Activity communication.