TabLayout+ViewPage建立关联setupWithViewPager（）出现的问题

Posted 2022-11-30 一如年少模样

xml：

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.study.yxrr.tablayoutviewpage.MainActivity">

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

        <android.support.design.widget.TabLayout
            android:id="@+id/id_tablayout"
            android:layout_width="match_parent"
            android:layout_height="50dip" />

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

    </LinearLayout>
</android.support.design.widget.CoordinatorLayout>

代码：

public class MainActivity extends AppCompatActivity 

private TabLayout mTl;
private ViewPager mVp;
@Override
protected void onCreate(Bundle savedInstanceState) 
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.activity_main);
    initView();



private void initView() 
    mTl = (TabLayout) findViewById(R.id.id_tablayout);
    mVp = (ViewPager) findViewById(R.id.id_vp);
    //添加两个tab
    mTl.addTab(mTl.newTab().setText("NBA"));
    mTl.addTab(mTl.newTab().setText("阅读"));
    mTl.addTab(mTl.newTab().setText("健康"));
    //让tablayout与viewpager建立关联关系
    mTl.setupWithViewPager(mVp);
    mVp.setAdapter(new PagerAdapter() 
        @Override
        public int getCount() 
            return 3;
        
        @Override
        public boolean isViewFromObject(View view, Object object) 
            return view == object;
        
        @Override
        public Object instantiateItem(ViewGroup container, int position) 
            TextView textView = new TextView(container.getContext());
            textView.setText("position:" + position);
            container.addView(textView);
            return textView;
        
        @Override
        public void destroyItem(ViewGroup container, int position, Object object) 
            container.removeView((View) object);
        

        @Override
        public CharSequence getPageTitle(int position) 
            if(position ==0) 
                return "NBA";
            else if (position==1) 
                return "阅读";
            else
            
                return "健康";
            
        
    );
 

代码中 我们给TabLayout添加了三个，如果我们补充协议getPageTitle方法是不会出现的，这个原因是因为tablayout与viewpager建立关联关系的时候，已经把tab全部remove了

源码如下：