如何更改放置在PreferenceFragment中的首选项的摘要

Question

I'm developing an app and I'm trying to follow Android guidelines and to use android studio templates. I'm having various troubles with preference activity and in particular I can't get access to a preference outside the fragment in which it's loaded, ie I need to modify the summary of a preference from the activity and not from the fragment, because trying to modify if inside the fragment is impossible given that it's a static class and the method which provides the new value for the summary is non-static (it's a get version method, which uses the getPackageManager non-static method). Is there a way to acromplish this?

Answer 1

You should be able to access the packageManager from within the fragment. For example:

version = getActivity().getPackageManager().
                getPackageInfo(getActivity().getPackageName(),  0).versionName;

And if you want to do it from the activity, you just need to get a reference to the preference.

First get a reference to the preference within the fragment:

Preference myPref;    

public void onCreate(){
    myPref = findPreference("myPref");
}

public Preference getMyPref(){
    return myPref;
}

And in the activity you can do:

myFragment.getMyPref().setSummary("Preference Summary");

You can also call a method on the Activity from the fragment and pass it the preference that you want to update the summary on.