java - ListFragment 更改尺寸

Question

我有一个具有两个 fragment (权重 3 和 2)线性布局的 Activity 。第一个 fragment 是一个列表 fragment 。它最初具有指定的权重高度，但是当列表变大时，它会变得更长并占据整个 Activity 布局，就像我将其高度设置为与父项匹配一样。

Activity XML

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <fragment
        android:id="@+id/fragment"
        android:name="com.example.students.StudentListFragment"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="3" />

    <fragment
        android:id="@+id/fragment2"
        android:name="com.example.students.StudentDetail"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="2" />
</LinearLayout>

第一个 fragment - 因为它是一个 listFragment，所以我们只有它的 java 文件。

/**
 * A fragment representing a list of Items.
 * <p/>
 * Activities containing this fragment MUST implement the {@link OnListFragmentInteractionListener}
 * interface.
 */

public class StudentListFragment extends ListFragment {
// TODO: Customize parameters
private int mColumnCount = 1;
Context CurrentContext;
LayoutInflater Inflater;

private OnListFragmentInteractionListener mListener;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
   View view = super.onCreateView(inflater,container,savedInstanceState);

    Inflater = inflater;
    // Set the adapter
    if (view instanceof RecyclerView) {
        Context context = view.getContext();
        RecyclerView recyclerView = (RecyclerView) view;
        if (mColumnCount <= 1) {
            recyclerView.setLayoutManager(new LinearLayoutManager(context));
        } else {
            recyclerView.setLayoutManager(new GridLayoutManager(context, mColumnCount));
        }
        recyclerView.setAdapter(new MyStudentRecyclerViewAdapter(DummyContent.ITEMS, mListener));
    }



    return view;
}


public void onStart()
{
    super.onStart();
    CurrentContext = Inflater.getContext();

    new GetListTask().execute();


}

@Override
public void onAttach(Context context) {
    super.onAttach(context);
    if (context instanceof OnListFragmentInteractionListener) {
        mListener = (OnListFragmentInteractionListener) context;
    } else {
        throw new RuntimeException(context.toString()
                + " must implement OnListFragmentInteractionListener");
    }
}

@Override
public void onDetach() {
    super.onDetach();
    mListener = null;
}

/**
 * This interface must be implemented by activities that contain this
 * fragment to allow an interaction in this fragment to be communicated
 * to the activity and potentially other fragments contained in that
 * activity.
 * <p/>
 * See the Android Training lesson <a href=
 * "http://developer.android.com/training/basics/fragments/communicating.html"
 * >Communicating with Other Fragments</a> for more information.
 */
public interface OnListFragmentInteractionListener {
    // TODO: Update argument type and name
    void onListFragmentInteraction(DummyItem item);
}

class GetListTask extends AsyncTask<Void,Void,Object>
{


    @Override
    protected Object doInBackground(Void[] voids) {
        //try
        {

            SQLhelper helper = new SQLhelper(CurrentContext);
            SQLiteDatabase database =  helper.getReadableDatabase();

            Cursor cursor;

            cursor = database.query("students", new String[]{"_id","USERNAME", "PASSWORD"}, "NOT roll = ?" ,new String[]{"-1"}, null, null, null);
            //cursor = database.query("students", new String[]{"_id","USERNAME", "PASSWORD"}, null, null, null, null, null);

            return cursor;


        }/* catch (Exception e) {
            return e;
        }*/
    }

    protected void onPostExecute(Object object) {
        if (object instanceof Cursor) {
            CursorAdapter listAdapter = new SimpleCursorAdapter(CurrentContext, android.R.layout.simple_list_item_1, (Cursor)object, new String[]{"USERNAME"}, new int[]{android.R.id.text1}, 0) {

            };

            setListAdapter(listAdapter);
        }
        else {
            new MyToast(CurrentContext, ((Exception)object).getMessage());
        }
    }
}

}

我希望它保持其高度，但看起来它不想这样做。

Answer 1

问题出在您的 xml 中:您主要缺少父线性布局中的权重总和，因此要解决此问题，只需将权重总和添加到父布局中并将 fragment 高度设置为 match_parent:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:weightSum="5"
   android:layout_height="match_parent">

    <fragment
        android:id="@+id/fragment"
        android:name="com.example.students.StudentListFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="3" />

    <fragment
        android:id="@+id/fragment2"
        android:name="com.example.students.StudentDetail"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="2" />
</LinearLayout>