findViewById returns null in fragment

问题:

I have problem using the findViewByID methond in a fragment.

The spinner in Spinner spinner = (Spinner) view.findViewById(R.id.tabsearchspinner_location); is always null. Please see the code below.

public class FragmentTabSearch extends SherlockFragment implements OnItemSelectedListener {  @Override public View onCreateView(LayoutInflater inflater, ViewGroup container,         Bundle savedInstanceState) {     // TODO Auto-generated method stub     View view = inflater.inflate(R.layout.fragment_tab_suggestions, container, false);      Spinner spinner = (Spinner) view.findViewById(R.id.tabsearchspinner_location);     ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this.getSherlockActivity(), R.array.spinner_location, android.R.layout.simple_spinner_item);     adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);     spinner.setAdapter(adapter);      return view; }  @Override public void onItemSelected(IcsAdapterView<?> parent, View view,         int position, long id) {     // TODO Auto-generated method stub  }  @Override public void onNothingSelected(IcsAdapterView<?> parent) {     // TODO Auto-generated method stub  } 

}

The layout file is as below (ps: I have already declared the id/tabsearchspinner_location in the values/ids.xml file): <item type="id" name="tabsearchspinner_location"></item>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" >  <Spinner     android:id="@id/tabsearchspinner_location"     android:layout_width="wrap_content"     android:layout_height="wrap_content" />  <ListView     android:id="@id/tablistview_search"     android:layout_width="match_parent"     android:layout_height="wrap_content" > </ListView> 

Any help is appreciated!

回答1:

Inflate your View without a ViewGroup, as it's simply inside your FragmentActivity:

View view = inflater.inflate(R.layout.fragment_tab_suggestions, null); 

And the way IDs are added inside the XML layout files is like this:

android:id="@+id/tabsearchspinner_location" 

As you can see, you're missing the +

回答2:

Sorry, I just found out that I inflated the wrong layout, so the findViewById method always returns null, thanks for all the help though.

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