Java Viewpager在片段内部不可见
我在主活动中有一个导航栏。它有5个项目 下面是该导航的getitem方法Java Viewpager在片段内部不可见,java,android,android-fragments,Java,Android,Android Fragments,我在主活动中有一个导航栏。它有5个项目 下面是该导航的getitem方法 @Override public Fragment getItem(int position) { switch (position){ case 0: return new ChatRoomPage(); case 1: return new TopicPage();
@Override
public Fragment getItem(int position) {
switch (position){
case 0:
return new ChatRoomPage();
case 1:
return new TopicPage();
case 2:
return new TopicPage();
case 3:
return new Leaderboard();
case 4:
return new Stats();
}
return new ChatRoomPage();
}
我为测试添加了TopicPage()
所以,主题页面是一个带有选项卡布局的片段。该片段使用tab视图显示了另外三个片段
案例2中的TopicPage()
工作正常
但在案例3中,显示了片段TopicPage()
。它还调用选项卡布局中的三个片段(在日志中获取消息)。但在ViewPager中不可见。并且,表格布局上的下划线不会使用动画从一个选项卡滑动到另一个选项卡。我必须手动滑动它
以及
当我添加一个片段,如Stats()
或leadboard()
时,它会起作用
截图
主题页onCreateview
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
v = inflater.inflate(R.layout.topic_page, container, false);
tabLayout = v.findViewById(R.id.tab);
pager = v.findViewById(R.id.pager);
pager.setOffscreenPageLimit(4);
tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
pager.setAdapter(new TopicPagerAdapter(getFragmentManager()));
tabLayout.setupWithViewPager(pager);
return v;
}
所以我不知道为什么我会遇到这个问题
需要帮助:(重写
TopicPage()
片段中名为setUserVisibilityHint()
在这个方法中,在return语句之后…写
如果(getActivity()!=null){viewPager.setAdapter(..youradapter);}
我认为它会工作。首先初始化viewPager的适配器,然后设置适配器…让我知道它是否工作。覆盖TopicPage()中名为setUserVisibilityHint()的片段中的方法。
在这个方法中,在return语句之后…写
如果(getActivity()!=null){viewPager.setAdapter(..youradapter);}
我认为它会工作。首先初始化viewPager的适配器,然后设置适配器…..让我知道它是否工作。MainActivity
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
tabLayout.addTab(tabLayout.newTab().setText("Tab 1"));
tabLayout.addTab(tabLayout.newTab().setText("Tab 2"));
tabLayout.addTab(tabLayout.newTab().setText("Tab 3"));
tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
final ViewPager viewPager = (ViewPager) findViewById(R.id.pager);
final PagerAdapter adapter = new PagerAdapter
(getSupportFragmentManager(), tabLayout.getTabCount());
viewPager.setAdapter(adapter);
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) {
}
});
}
片段的PagerAdapter
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:
TabFragment1 tab1 = new TabFragment1();
return tab1;
case 1:
TabFragment2 tab2 = new TabFragment2();
return tab2;
case 2:
TabFragment3 tab3 = new TabFragment3();
return tab3;
default:
return null;
}
}
@Override
public int getCount() {
return mNumOfTabs;
}
}
public class TabFragment1 extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.tab_fragment_1, container, false);
}
FirstFragment
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:
TabFragment1 tab1 = new TabFragment1();
return tab1;
case 1:
TabFragment2 tab2 = new TabFragment2();
return tab2;
case 2:
TabFragment3 tab3 = new TabFragment3();
return tab3;
default:
return null;
}
}
@Override
public int getCount() {
return mNumOfTabs;
}
}
public class TabFragment1 extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.tab_fragment_1, container, false);
}
}main活动
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
tabLayout.addTab(tabLayout.newTab().setText("Tab 1"));
tabLayout.addTab(tabLayout.newTab().setText("Tab 2"));
tabLayout.addTab(tabLayout.newTab().setText("Tab 3"));
tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
final ViewPager viewPager = (ViewPager) findViewById(R.id.pager);
final PagerAdapter adapter = new PagerAdapter
(getSupportFragmentManager(), tabLayout.getTabCount());
viewPager.setAdapter(adapter);
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) {
}
});
}
片段的PagerAdapter
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:
TabFragment1 tab1 = new TabFragment1();
return tab1;
case 1:
TabFragment2 tab2 = new TabFragment2();
return tab2;
case 2:
TabFragment3 tab3 = new TabFragment3();
return tab3;
default:
return null;
}
}
@Override
public int getCount() {
return mNumOfTabs;
}
}
public class TabFragment1 extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.tab_fragment_1, container, false);
}
FirstFragment
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:
TabFragment1 tab1 = new TabFragment1();
return tab1;
case 1:
TabFragment2 tab2 = new TabFragment2();
return tab2;
case 2:
TabFragment3 tab3 = new TabFragment3();
return tab3;
default:
return null;
}
}
@Override
public int getCount() {
return mNumOfTabs;
}
}
public class TabFragment1 extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.tab_fragment_1, container, false);
}
}您是否介意尝试此操作。当在另一个片段中显示片段时,请使用getChildFragmentManager()而不是getSupportFragmentManager()初始化页面适配器,方法如下:
pageAdapter = new FragmentHomeAdapter(getChildFragmentManager(), pageList);
请尝试一下。当在另一个片段中显示片段时,请使用getChildFragmentManager()而不是getSupportFragmentManager()初始化页面适配器,方法如下:
pageAdapter = new FragmentHomeAdapter(getChildFragmentManager(), pageList);
你有嵌套的viewPager吗?@elmorabea yeahIf用户正在查看案例1或案例2 ie(主题页)用户将如何返回到主选项卡布局,即初始/父布局,您有屏幕截图吗?屏幕截图..@lib4Glad以获取帮助。我将其添加为答案。请接受。您有嵌套的ViewPager吗?@elmorabea yeahIf用户正在查看案例1或案例2 ie(主题页)用户将如何返回到主选项卡布局,即初始/父布局,你有屏幕截图吗?屏幕截图..@lib4Glad以了解其帮助。我将其添加为答案。请接受。尝试。但它不起作用。案例1主题页在完成后也不显示。.代码@Override public void setUserVisibleHint(布尔isVisibleToUser){super.setUserVisibleHint(isVisibleToUser);if(getActivity()!=null){pager.setAdapter(新的TopicPagerAdapter(getFragmentManager());}@NoobCoder您得到解决方案了吗?还是我应该为您粘贴整个代码?我仍然面临这个问题。@nihal_softy@NoobCoder据我所知,你想在片段内使用查看寻呼机?对吗?是的..检查此ss..已尝试。但它不起作用。案例1主题页在完成后也不显示..代码@Override public void seTuServiceHint(boolean isVisibleToUser){super.setUserVisibleTouser(isVisibleToUser);if(getActivity()!=null){pager.setAdapter(新主题PageRadapter(getFragmentManager());}@NoobCoder您得到解决方案了吗?还是我应该为您粘贴整个代码?我仍然面临这个问题。@nihal_softy@NoobCoder根据我的理解,你想在片段内使用查看寻呼机?对吗?是的..检查这个ss。