OnTabselected无效

Question

我有一个包含Tablayout和viewpager的XML布局。我在片段中附加了带tablayout的viewpager，我希望在点击标签和交换时更改片段。

<?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"
    android:orientation="vertical">

    <android.support.design.widget.TabLayout
        android:id="@+id/tabs"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#262626"
        app:tabIndicatorColor="#FFF6EEF1"
        app:tabSelectedTextColor="#FFF9EFC6"
        app:tabTextColor="#FFF6EEF1"
        app:tabGravity="center"

        android:layout_alignParentBottom="true"
        android:layout_alignParentStart="true" />
    <android.support.v4.view.ViewPager
        android:id="@+id/pager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
     >
    </android.support.v4.view.ViewPager>

</RelativeLayout>

Java文件是：

package com.example.eventor;
import android.os.Bundle;
import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.view.ViewPager;
import android.support.v7.app.ActionBar;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;


import com.example.eventor.tabfragments.CalanderFragment;
import com.example.eventor.tabfragments.HomeFragments;
import com.example.eventor.tabfragments.SearchFragment;
import com.example.eventor.tabfragments.UserFragment;

public class TabFragment extends Fragment implements ActionBar.TabListener {
    public static TabLayout tabLayout;
    public static ViewPager viewPager;
    public static int int_items = 4;
    private int[] tabIcons = new int[]{

            R.drawable.ic_home_outline_white_48dp,
            R.drawable.ic_date_range_black_48dp,
            R.drawable.ic_search_black_48dp,
            R.drawable.ic_person_outline_black_48dp

    };
    FragmentAdapter fr = new FragmentAdapter(getFragmentManager());

    public TabFragment() {

    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View x = inflater.inflate(R.layout.tablayout,container,false);
        tabLayout = (TabLayout) x.findViewById(R.id.tabs);
        viewPager = (ViewPager) x.findViewById(R.id.pager);
        tabLayout.setupWithViewPager(viewPager);
        viewPager.setAdapter(new FragmentAdapter(getChildFragmentManager()));

        tabLayout.getTabAt(0).setIcon(tabIcons[0]);
        tabLayout.getTabAt(1).setIcon(tabIcons[1]);
        tabLayout.getTabAt(2).setIcon(tabIcons[2]);
        tabLayout.getTabAt(3).setIcon(tabIcons[3]);
        return x;
    }

    @Override
    public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft) {

        viewPager.setCurrentItem(tab.getPosition(),true);
    }

    @Override
    public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction ft) {

    }

    @Override
    public void onTabReselected(ActionBar.Tab tab, FragmentTransaction ft) {

    }

    public class FragmentAdapter extends FragmentPagerAdapter {

        @Override
        public CharSequence getPageTitle(int position) {
            switch (position) {
                case 0:
                    return "home";
                case 1:
                    return "calander";
                case 2:
                    return "search";
                case 3:
                    return "profile";

            }

     return null;
        }


        public FragmentAdapter(FragmentManager fm) {
            super(fm);

        }


        public Fragment getItem(int position) {
            switch (position) {
                case 0:
                    return new HomeFragments();
                case 1:
                    return new CalanderFragment();
                case 2:
                    return new SearchFragment();
                case 3:
                    return new UserFragment();
            }
            return null;
        }

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


    }
}

单击选项卡时，它不会显示相应的片段。但是交换片段很好。 感谢

Answer 1

我建议你使用android studio模板作为Tabbed活动的起点。 文件＆gt;＆gt;新＆gt;＆gt; acitity＆gt;＆gt;标签式活动

Answer 2

试试这个：在你的xml中放置viewpager下面的tablayout。 android:layout_below="@+id/tabs"

 <?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"
    android:orientation="vertical">


    <android.support.v4.view.ViewPager
        android:id="@+id/pager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@+id/tabs"></android.support.v4.view.ViewPager>


    <android.support.design.widget.TabLayout
        android:id="@+id/tabs"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:background="#262626"
        app:tabGravity="center"
        app:tabIndicatorColor="#FFF6EEF1"
        app:tabSelectedTextColor="#FFF9EFC6"
        app:tabTextColor="#FFF6EEF1" />


</RelativeLayout>

代码中的

：在ActionBar.TabListener

中使用此代替onCreate()

 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)
        {

        }
    });