ViewPager 不会膨胀所有 XML 布局文件

Question

我想在我的应用程序的选项卡中创建选项卡。我在我的 MainActivity XML 文件中创建了一个 TabLayout 以及 ViewPager。然后，我创建了另一个 XML 文件，其中包含内部 TabLayout 及其对应的 ViewPager。现在，当我运行我的应用程序时，我可以看到除了我的第一个选项卡（主页图标选项卡）之外的所有其他选项卡的膨胀视图。此外，当我选择了一个没有被看到的内部选项卡时，我有一个 CardView 要显示。请帮忙！ 这是我的 MainActivity.java 代码：

public class MainActivity extends AppCompatActivity {

    ViewPager viewPagerOuter, viewPagerInner;
    TabLayout tabLayoutouter, tabLayoutinner;

    public static class InnerFragment extends Fragment{
    private static final String TAB_POSITION = "tab_position";
    View rootView;
    public InnerFragment(){

    }
    public static InnerFragment newInstance(int tabPosition){
        InnerFragment fragment = new InnerFragment();
        Bundle args = new Bundle();
        args.putInt(TAB_POSITION, tabPosition);
        fragment.setArguments(args);
        return fragment;
    }
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
        Bundle args = getArguments();
        int tabPosition = args.getInt(TAB_POSITION);
        switch (tabPosition){
            case 0:{
                rootView = inflater.inflate(R.layout.card_view_layout, container, false);
                break;
            }
            case 1:{
                TextView tv = new TextView(getActivity());
                tv.setGravity(Gravity.CENTER);
                tv.setText("Text in tab #" + tabPosition);
                rootView = tv;
                break;
            }
        }
        return rootView;
    }
}
static class InnerPagerAdapter extends FragmentStatePagerAdapter{
    public InnerPagerAdapter(FragmentManager fm){
        super(fm);
    }
    @Override
    public Fragment getItem(int position) {
        return InnerFragment.newInstance(position);
    }

    @Override
    public int getCount() {
        return 2;
    }

    @Override
    public CharSequence getPageTitle(int position){
        String x = "";
        switch (position){
            case 0:
                x = "feed"; break;
            case 1:
                x = "events"; break;
        }
        return x;
    }
}

public static class OuterFragment extends Fragment{
    private static final String TAB_POSITION1 = "tab_position";
    View rootView;
    public OuterFragment(){

    }
    public static OuterFragment newInstance(int tabPosition){
        OuterFragment fragment1 = new OuterFragment();
        Bundle args1 = new Bundle();
        args1.putInt(TAB_POSITION1, tabPosition);
        fragment1.setArguments(args1);
        return fragment1;
    }
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater1, ViewGroup container1, Bundle savedInstanceState){
        Bundle args1 = getArguments();
        int tabPosition = args1.getInt(TAB_POSITION1);
        switch (tabPosition){
            case 0:{
                rootView = inflater1.inflate(R.layout.inner_tab_layout, container1, false);
                break;
            }
            default:{
                TextView tv = new TextView(getActivity());
                tv.setGravity(Gravity.CENTER);
                tv.setText("Text in tab #" + tabPosition);
                rootView = tv;
                break;
            }
        }
        return rootView;
    }
}
static class OuterPagerAdapter extends FragmentStatePagerAdapter{
    public OuterPagerAdapter(FragmentManager fm){
        super(fm);
    }
    @Override
    public Fragment getItem(int position) {
        return OuterFragment.newInstance(position);
    }

    @Override
    public int getCount() {
        return 4;
    }

    @Override
    public CharSequence getPageTitle(int position) {return null;}
}
final int icons[] = new int[]{R.drawable.ic_chat_black_24dp, R.drawable.ic_home_black_24dp, R.drawable.ic_notifications_black_24dp, R.drawable.ic_person_black_24dp};
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    InnerPagerAdapter innerPagerAdapter = new InnerPagerAdapter(getSupportFragmentManager());
    OuterPagerAdapter outerPagerAdapter = new OuterPagerAdapter(getSupportFragmentManager());

    viewPagerOuter = (ViewPager) findViewById(R.id.viewpagerouter);
    viewPagerOuter.setAdapter(outerPagerAdapter);
    tabLayoutouter = (TabLayout) findViewById(R.id.tablayoutouter);

    final LayoutInflater factory = getLayoutInflater();
    final View view = factory.inflate(R.layout.inner_tab_layout, null);
    viewPagerInner = (ViewPager) view.findViewById(R.id.viewpagerinner);
    viewPagerInner.setAdapter(innerPagerAdapter);
    tabLayoutinner = (TabLayout) view.findViewById(R.id.tabLayoutinner);
    tabLayoutinner.setupWithViewPager(viewPagerInner);
}
}

这是 MainActivity 的 XML 文件：

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

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <android.support.design.widget.TabLayout
        android:id="@+id/tablayoutouter"
        android.support.tabIndicatorColor="?attr/colorPrimary"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="?attr/colorPrimary"
        android:theme="@style/ThemeOverlay.AppCompat.Dark"
        app:tabGravity="fill"
        app:tabIndicatorColor="@color/colorPrimary"
        app:tabSelectedTextColor="@android:color/background_light">

    <android.support.v4.view.ViewPager
        android:id="@+id/viewpagerouter"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1" >

    </android.support.v4.view.ViewPager>

</LinearLayout>

<android.support.design.widget.FloatingActionButton
    android:id="@+id/fab"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_alignParentRight="true"
    android:layout_marginRight="16dp"
    android:layout_marginBottom="16dp"
    android:src="@drawable/ic_create_black_24dp" />

</RelativeLayout>

这是 inner_tab_layout.xml

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

<android.support.design.widget.TabLayout
    android:id="@+id/tabLayoutinner"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:tabGravity="fill"
    app:tabIndicatorColor="@color/colorPrimaryDark"
    app:tabSelectedTextColor="@color/colorBlack">
</android.support.design.widget.TabLayout>

<android.support.v4.view.ViewPager
    android:id="@+id/viewpagerinner"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="1" />

</LinearLayout>

我很抱歉发布这么长的代码。请不要介意..

Answer 1

将viewPagerInner、tabLayoutinner 和innerPagerAdapter 代码移动到OuterFragment。

1.如下更新您的OuterFragment：

public static class OuterFragment extends Fragment {
    private static final String TAB_POSITION1 = "tab_position";
    View rootView;

    ViewPager viewPagerInner;
    TabLayout tabLayoutinner;

    public OuterFragment(){

    }
    public static OuterFragment newInstance(int tabPosition){
        OuterFragment fragment1 = new OuterFragment();
        Bundle args1 = new Bundle();
        args1.putInt(TAB_POSITION1, tabPosition);
        fragment1.setArguments(args1);
        return fragment1;
    }
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater1, ViewGroup container1, Bundle savedInstanceState){
        Bundle args1 = getArguments();
        int tabPosition = args1.getInt(TAB_POSITION1);
        switch (tabPosition){
            case 0:{
                rootView = inflater1.inflate(R.layout.inner_tab_layout, container1, false);

                viewPagerInner = (ViewPager) rootView.findViewById(R.id.viewpagerinner);
                tabLayoutinner = (TabLayout) rootView.findViewById(R.id.tabLayoutinner);

                InnerPagerAdapter innerPagerAdapter = new InnerPagerAdapter(getActivity().getSupportFragmentManager());

                viewPagerInner.setAdapter(innerPagerAdapter);
                tabLayoutinner.setupWithViewPager(viewPagerInner);

                break;
            }
            default:{
                TextView tv = new TextView(getActivity());
                tv.setGravity(Gravity.CENTER);
                tv.setText("Text in tab #" + tabPosition);
                rootView = tv;
                break;
            }
        }
        return rootView;
    }
}

2.更新onCreate()方法如下：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    viewPagerOuter = (ViewPager) findViewById(R.id.viewpagerouter);
    tabLayoutouter = (TabLayout) findViewById(R.id.tablayoutouter);

    OuterPagerAdapter outerPagerAdapter = new OuterPagerAdapter(getSupportFragmentManager());

    viewPagerOuter.setAdapter(outerPagerAdapter);
    tabLayoutouter.setupWithViewPager(viewPagerOuter);
}

希望这会奏效~