Android：TabLayout没有显示任何标签
作者：互联网
第一次使用com.android.support:design:23.1.1,并且遇到一些问题让TabLayout工作.
我的应用程序基本上是这样设置的：
>一个名为LandingActivity的主要活动,其中包含一个带有菜单项的DrawerLayout.
>选择菜单项时,我将不同的片段加载到LandingActivity中的FrameLayout中.
>某些加载的片段应在顶部显示标签,有些则不应.
我的问题是,在应该在顶部显示标签的Fragment上,它在导航栏中有额外的空间,就像它应该有标签一样,但没有任何显示.
码：
activity_landing.xml
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<!-- This LinearLayout represents the contents of the screen -->
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<!-- The ActionBar displayed at the top -->
<include
layout="@layout/tool_bar"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<!-- The main content view where fragments are loaded -->
<FrameLayout
android:id="@+id/flContent"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
<!-- The navigation drawer that comes from the left -->
<!-- Note that `android:layout_gravity` needs to be set to 'start' -->
<android.support.design.widget.NavigationView
android:id="@+id/nvView"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="start"
android:background="@android:color/white"
app:menu="@menu/drawer" />
我加载片段的LandingActivity：
public void selectDrawerItem(MenuItem menuItem) {
// Create a new fragment and specify the planet to show based on
// position
Fragment fragment = null;
switch(menuItem.getItemId()) {
case R.id.drawer_home:
fragment = HomeFragment.newInstance();
break;
case R.id.drawer_customize:
fragment = CustomizeFragment.newInstance();
break;
default:
fragment = HomeFragment.newInstance();
}
// Insert the fragment by replacing any existing fragment
FragmentManager fragmentManager = getSupportFragmentManager();
fragmentManager.beginTransaction().replace(R.id.flContent, fragment).commit();
home_fragment.xml(带有标签的一个)
<android.support.design.widget.AppBarLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.design.widget.TabLayout
android:id="@+id/tabLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabMode="fixed"
app:tabGravity="fill"
/>
<android.support.v4.view.ViewPager
android:id="@+id/viewpager"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@android:color/white"/>
HomeFragment.java
public class HomeFragment extends Fragment {
public static HomeFragment newInstance() {
Bundle args = new Bundle(); alreadySelectedFollowingInfo);
HomeFragment fragment = new HomeFragment();
fragment.setArguments(args);
return fragment;
}
public HomeFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final View v = inflater.inflate(R.layout.fragment_home, container, false);
final TabLayout tabLayout = (TabLayout) v.findViewById(R.id.tabLayout);
tabLayout.addTab(tabLayout.newTab().setText("One"));
tabLayout.addTab(tabLayout.newTab().setText("Two"));
final ViewPager viewPager = (ViewPager) v.findViewById(R.id.viewpager);
viewPager.setAdapter(new PagerAdapter
(getFragmentManager(), tabLayout.getTabCount()));
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
@Override
public void onTabSelected(TabLayout.Tab tab) {
viewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(TabLayout.Tab tab) {
}
@Override
public void onTabReselected(TabLayout.Tab tab) {
}
});
tabLayout.post(new Runnable() {
@Override
public void run() {
tabLayout.setupWithViewPager(viewPager);
}
});
return inflater.inflate(R.layout.fragment_home, container, false);
}
public class PagerAdapter extends FragmentStatePagerAdapter {
int mNumOfTabs;
public PagerAdapter(FragmentManager fm, int NumOfTabs) {
super(fm);
this.mNumOfTabs = NumOfTabs;
}
@Override
public Fragment getItem(int position) {
switch (position) {
case 0:
BlogFragment tab1 = BlogFragment.newInstance();
return tab1;
case 1:
TrendingFragment tab2 = TrendingFragment.newInstance();
return tab2;
default:
return null;
}
}
@Override
public int getCount() {
return mNumOfTabs;
}
}
}
可能不相关,但在activity_landing.xml中使用了tool_bar.xml
<android.support.v7.widget.Toolbar
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/toolbar"
android:layout_height="wrap_content"
android:layout_width="match_parent"
android:fitsSystemWindows="true"
android:minHeight="?attr/actionBarSize"
app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
android:background="?attr/colorPrimary">
这就是我所拥有的一切.无法弄清楚发生了什么.
编辑：
新代码：
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final View v = inflater.inflate(R.layout.fragment_home, container, false);
ViewPager viewPager = (ViewPager) v.findViewById(R.id.viewpager);
setupViewPager(viewPager);
TabLayout tabLayout = (TabLayout) v.findViewById(R.id.tabLayout);
tabLayout.setupWithViewPager(viewPager);
return v;
}
private void setupViewPager(ViewPager viewPager) {
PagerAdapter adapter = new PagerAdapter(getFragmentManager());
adapter.addFragment(BlogFragment.newInstance(), "ONE");
adapter.addFragment(TrendingFragment.newInstance(), "TWO");
viewPager.setAdapter(adapter);
}
class PagerAdapter extends FragmentPagerAdapter {
private final List<Fragment> mFragmentList = new ArrayList<>();
private final List<String> mFragmentTitleList = new ArrayList<>();
public PagerAdapter(FragmentManager manager) {
super(manager);
}
@Override
public Fragment getItem(int position) {
return mFragmentList.get(position);
}
@Override
public int getCount() {
return mFragmentList.size();
}
public void addFragment(Fragment fragment, String title) {
mFragmentList.add(fragment);
mFragmentTitleList.add(title);
}
@Override
public CharSequence getPageTitle(int position) {
return mFragmentTitleList.get(position);
}
}
解决方法:
return inflater.inflate(R.layout.fragment_home, container, false);
在你的onCreateView中意味着你返回一个新膨胀的主片段而没有任何初始化代码.
您应该返回在onCreateView开头创建的视图：
return v;
提供标签标题的示例PagerAdapter：
public class PagerAdapter extends FragmentPagerAdapter {
private final List<Fragment> mFragments = new ArrayList<>();
private final List<String> mFragmentTitles = new ArrayList<>();
public PagerAdapter(FragmentManager fm) {
super(fm);
}
public void addFragment(Fragment fragment, String title) {
mFragments.add(fragment);
mFragmentTitles.add(title);
}
@Override
public Fragment getItem(int position) {
return mFragments.get(position);
}
@Override
public int getCount() {
return mFragments.size();
}
@Override
public CharSequence getPageTitle(int position) {
return mFragmentTitles.get(position);
}
}
因此,您重构的onCreateView代码将类似于：
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_home, container, false);
final TabLayout tabLayout = (TabLayout) v.findViewById(R.id.tabLayout);
final ViewPager viewPager = (ViewPager) v.findViewById(R.id.viewpager);
PagerAdapter adapter = new PagerAdapter(getFragmentManager());
adapter.addFragment(BlogFragment.newInstance(), "One");
adapter.addFragment(TrendingFragment.newInstance(), "Two");
viewPager.setAdapter(adapter);
tabLayout.post(new Runnable() {
@Override
public void run() {
tabLayout.setupWithViewPager(viewPager);
}
});
return v;
}
标签：android,android-fragments,material-design,androiddesignsupport 来源： https://codeday.me/bug/20190528/1168071.html