Where/How to getIntent().getExtras() in an Android Fragment?
AndroidAndroid IntentAndroid FragmentsAndroid ActivityAndroid Problem Overview
With Activities, I used to do this:
In Activity 1:
Intent i = new Intent(getApplicationContext(), MyFragmentActivity.class);
i.putExtra("name", items.get(arg2));
i.putExtra("category", Category);
startActivity(i);
In Activity 2:
Item = getIntent().getExtras().getString("name");
How do you do this using Fragments? I am using the compatibility library v4 also.
Does it go in the FragmentActivity? Or the actual Fragment? And Which Method does it go in? onCreate? onCreateView? another?
And can I see example code please?
EDIT: It is worth noting I am trying to keep Activity 1 as an Activity (or actually ListActivity where I am passing the intent of the listitem when clicked) and then pass to a set of tabbed-fragments (through a Fragment Activity) and I need either tab to be able to get the extras. (I hope this is possible?)
Android Solutions
Solution 1 - Android
you can still use
String Item = getIntent().getExtras().getString("name");
in the fragment
, you just need call getActivity()
first:
String Item = getActivity().getIntent().getExtras().getString("name");
This saves you having to write some code.
Solution 2 - Android
What I tend to do, and I believe this is what Google intended for developers to do too, is to still get the extras from an Intent
in an Activity
and then pass any extra data to fragments by instantiating them with arguments.
There's actually an example on the Android dev blog that illustrates this concept, and you'll see this in several of the API demos too. Although this specific example is given for API 3.0+ fragments, the same flow applies when using FragmentActivity
and Fragment
from the support library.
You first retrieve the intent extras as usual in your activity and pass them on as arguments to the fragment:
public static class DetailsActivity extends FragmentActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// (omitted some other stuff)
if (savedInstanceState == null) {
// During initial setup, plug in the details fragment.
DetailsFragment details = new DetailsFragment();
details.setArguments(getIntent().getExtras());
getSupportFragmentManager().beginTransaction().add(
android.R.id.content, details).commit();
}
}
}
In stead of directly invoking the constructor, it's probably easier to use a static method that plugs the arguments into the fragment for you. Such a method is often called newInstance
in the examples given by Google. There actually is a newInstance
method in DetailsFragment
, so I'm unsure why it isn't used in the snippet above...
Anyways, all extras provided as argument upon creating the fragment, will be available by calling getArguments()
. Since this returns a Bundle
, its usage is similar to that of the extras in an Activity
.
public static class DetailsFragment extends Fragment {
/**
* Create a new instance of DetailsFragment, initialized to
* show the text at 'index'.
*/
public static DetailsFragment newInstance(int index) {
DetailsFragment f = new DetailsFragment();
// Supply index input as an argument.
Bundle args = new Bundle();
args.putInt("index", index);
f.setArguments(args);
return f;
}
public int getShownIndex() {
return getArguments().getInt("index", 0);
}
// (other stuff omitted)
}