我需要在一个片段中放置ViewPager,但我有两个片段,第一个是我的菜单,第二个片段我想用作ViewPagerIndicator。
但是一个片段不能包含另一个片段...那我需要怎么做?
我需要在一个片段中放置ViewPager,但我有两个片段,第一个是我的菜单,第二个片段我想用作ViewPagerIndicator。
但是一个片段不能包含另一个片段...那我需要怎么做?
从Android 4.2开始,支持嵌套片段。http://developer.android.com/about/versions/android-4.2.html#NestedFragments支持库现在也包括了旧版Android版本的支持。
因此,您可以像这样做:
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
ViewPager mViewPager = (ViewPager) view.findViewById(R.id.viewPager);
mViewPager.setAdapter(new MyAdapter(getChildFragmentManager()));
}
完整实现在此处可用:https://github.com/marcoRS/nested-fragments/tree/master/src/com/burnside/digital/nestedfragments
如果你想在Fragment内部获取FragmentManager
,你必须使用getChildFragmentManager()
,而不是使用getSupportFragmentManager()
。
但是,你不应该使用FragmentStatePagerAdapter
,而应该使用FragmentPagerAdapter
。
FragmentPagerAdapter
拯救了我的一天。这已经发生了两次,但我直到看到这个才意识到。原因是:如果您尝试在一个片段中的ViewPager中使用FragmentStatePagerAdapter,如果您导航到另一页并返回,则您的选项菜单可能会混乱(或根本不显示)。 - eddym在Fragments内,只需使用getChildFragmentManager()代替getSupportFragmentManager()。
new ViewPagerAdapter(getChildFragmentManager());
new ViewPagerAdapter(getSupportFragmentManager());
fragment_sample.xml
布局<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<com.google.android.material.tabs.TabLayout
android:id="@+id/tablayout"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<androidx.viewpager.widget.ViewPager
android:id="@+id/viewpager"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1" />
</LinearLayout>
SampleFragment.java
类public class SampleFragment extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View fragmentView = inflater.inflate(R.layout.fragment_sample, container, false);
return fragmentView;
}
@Override
public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
// find views by id
ViewPager viewPager = view.findViewById(R.id.viewpager);
TabLayout tabLayout = view.findViewById(R.id.tablayout);
// attach tablayout with viewpager
tabLayout.setupWithViewPager(viewPager);
ViewPagerAdapter adapter = new ViewPagerAdapter(getChildFragmentManager());
// add your fragments
adapter.addFrag(new SampleFragment(), "Tab1");
adapter.addFrag(new SampleFragment2(), "Tab2");
adapter.addFrag(new SampleFragment3(), "Tab3");
// set adapter on viewpager
viewPager.setAdapter(adapter);
}
}
ViewPagerAdapter.java
类// common adapter for all view pager in your project.
public class ViewPagerAdapter extends FragmentStatePagerAdapter {
private final List<Fragment> mFragmentList = new ArrayList<>();
private final List<String> mFragmentTitleList = new ArrayList<>();
public ViewPagerAdapter(FragmentManager manager) {
super(manager);
}
@Override
public Fragment getItem(int position) {
return mFragmentList.get(position);
}
@Override
public int getCount() {
return mFragmentList.size();
}
@Override
public CharSequence getPageTitle(int position) {
return mFragmentTitleList.get(position);
}
public void addFrag(Fragment fragment) {
mFragmentList.add(fragment);
mFragmentTitleList.add("");
}
public void addFrag(Fragment fragment, String title) {
mFragmentList.add(fragment);
mFragmentTitleList.add(title);
}
}
重要相关链接
adapter.addFrag(new SampleFragment(), "Tab1");
中,SampleFragment()
应该被改为SampleFragment1()
,因为SampleFragment()
已经被定义为持有ViewPager
的片段。@Khemraj - Hadas Kaminsky这是可能的。尝试在view_pager_fragment.xml文件中编写以下代码:
<android.support.design.widget.AppBarLayout
android:id="@+id/appBarLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">
<android.support.design.widget.TabLayout
android:id="@+id/tab"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="@+id/viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior" />
ViewPagerFragment
ViewPager viewPager;
TabLayout tabLayout;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.tracks, container, false);
viewPager = (ViewPager) view.findViewById(R.id.viewpager);
tabLayout = (TabLayout) view.findViewById(R.id.tab);
return view;
}
@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
setupViewPager(viewPager);
tabLayout.setupWithViewPager(viewPager);
tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
@Override
public void onTabSelected(TabLayout.Tab tab) {
}
@Override
public void onTabUnselected(TabLayout.Tab tab) {
}
@Override
public void onTabReselected(TabLayout.Tab tab) {
}
});
}
private void setupViewPager(ViewPager viewPager) {
ViewPagerAdapter viewPagerAdapter = new ViewPagerAdapter(getChildFragmentManager());``
viewPager.setAdapter(viewPagerAdapter);
}
private class ViewPagerAdapter extends FragmentPagerAdapter {
public ViewPagerAdapter(FragmentManager fragmentManager) {
super(fragmentManager);
}
@Override
public Fragment getItem(int position) {
if(position == 0) return new FirstFragment();
if(position == 1) return new SecoundFragment();
if(position == 2) return new LoginFragment();
throw new IllegalStateException("Position is unexpectedly " + position);
}
@Override
public int getCount() {
return 3;
}
@Override
public CharSequence getPageTitle(int position) {
if(position == 0) return "First";
if(position == 1) return "Secound";
if(position == 2) return "Login";
throw new IllegalStateException("Position is unexpectedly " + position);
}
}
<android.support.v4.view.ViewPager
android:id="@+id/pager"
android:layout_width="match_parent"
android:layout_height="0px"
android:layout_weight="1" >
</android.support.v4.view.ViewPager>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="0"
android:gravity="center"
android:measureWithLargestChild="true"
android:orientation="horizontal" >
<Button
android:id="@+id/first"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="First" >
</Button>
<Button
android:id="@+id/last"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Last" >
</Button>
</LinearLayout>
Source: http://www.truiton.com/2013/05/android-fragmentpageradapter-example/