fragments and onConfigurationChanged

问题

I'm trying to do something I do with activities, but within a fragment. What I do is using activities:

First stop the activity restarts when rotating the device android:configChanges="keyboardHidden|orientation|screenSize"

in my activity add:

@Override
public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged(newConfig);

 setContentView(R.layout.main);
}

So get the activity does not restart, but reloading the main.xml, to use the layout-land

Now I have an activity showing viewpager, which contains three fragments. Everything works properly. Detection of the rotation is in the fragments

public class FRG_map_web extends Fragment  {

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);

        Log.i("myLogs", "Rotation");

    }

The problem is that the fragment not use setContentView(R.layout.main); this is the code:

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        view = inflater.inflate(R.layout.frg.myFragment, null); 

I tried to use:

LayoutInflater inflater = inflater = (LayoutInflater) getApplicationContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);

view = inflater.inflate(R.layout.frg.myFragment, null); 

...

LayoutInflater vi = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);

view = inflater.inflate(R.layout.frg.myFragment, null); 

...

LayoutInflater inflater = (LayoutInflater) context.getSystemService( Context.LAYOUT_INFLATER_SERVICE );

view = inflater.inflate(R.layout.frg.myFragment, null); 

...

LayoutInflater li = LayoutInflater.from(context);

and different ways, but always without success I can not inflate properly.

Can anyone tell me how I have to do?

Thanks in advance, I appreciate the help

Regards

回答1:

If I understand correctly, you don't want to the fragment to reload on each rotation. Instead you want to relayout the views and update them with information you already have.

public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged(newConfig);

    // Get a layout inflater (inflater from getActivity() or getSupportActivity() works as well)
    LayoutInflater inflater = (LayoutInflater) getApplicationContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    View newView = inflater.inflate(R.layout.frg.myFragment, null);
    // This just inflates the view but doesn't add it to any thing.
    // You need to add it to the root view of the fragment
    ViewGroup rootView = (ViewGroup) getView();
    // Remove all the existing views from the root view.
    // This is also a good place to recycle any resources you won't need anymore
    rootView.removeAllViews();
    rootView.addView(newView);
    // Viola, you have the new view setup
}

According to the documentation (getView()), getView() returns the same view that you returned from your onCreateView() but it does not. It actually return the parent of the view you returned in onCreateView() which is exactly what you need. getView() will return an instance of NoSaveStateFrameLayout, which is used specifically for Fragments as its root view.

Hope this helps.

回答2:

Have you considered retaining your fragment instances? See Fragment#setRetainInstance.

Allow your Activity to be recreated (do not specify android:configChanges) but retain your fragment instances across orientation changes. If all the heavy lifting happens in Fragment#onCreate this should work fine. onCreate() will not be called again since the fragment is not being re-created.

回答3:

I could do it by re-attaching the fragment within onConfigurationChanged:

   @Override
   public void onConfigurationChanged(Configuration newConfig)
    {
        getActivity().detachFragment(this);

        super.onConfigurationChanged(newConfig);

        ....

        getActivity().attachFragment(this);
    }

Remember that by detaching and attaching your fragment you will be only working with its view. But the fragment state is "saved" in the Fragment manager.

回答4:

Maybe you can try use

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    view = inflater.inflate(R.layout.frg.myFragment, container, false);
}

. In any case, the fragment still has to be destroyed and recreated, why not let Android handle it automatically by restarting the activity? If there is any data to keep, you can save it in onSavedInstanceState(). Setting android:configChanges="keyboardHidden|orientation|screenSize" is not recommended in Android.

回答5:

You can try to detach e attach the fragment:

@Override
public void onConfigurationChanged(Configuration newConfig) {
    FragmentManager fragmentManager = getFragmentManager();
    if (fragmentManager != null) {
        fragmentManager.beginTransaction().detach(this).commitAllowingStateLoss();
    }
    super.onConfigurationChanged(newConfig);
    if (fragmentManager != null) {
        fragmentManager.beginTransaction().attach(this).commitAllowingStateLoss();
    }
}

来源：https://stackoverflow.com/questions/16282739/fragments-and-onconfigurationchanged