解釋下為什么會(huì)刷新失敺褂凇：原因是Fragment在adapter中會(huì)形成緩存翘簇，在每次創(chuàng)建前都會(huì)去對(duì)比一下此Fragment是否存在撬码，這就是造成刷新不是我們預(yù)想的情況出現(xiàn)
步驟如下：
1、新建類(lèi)并繼承Fragment版保，接受數(shù)據(jù)完善布局
2呜笑、創(chuàng)建類(lèi)并繼承 FragmentStatePagerAdapter 夫否，重寫(xiě)其內(nèi)部方法 ，并重寫(xiě)getItemPosition()將返回值設(shè)置為PagerAdapter.POSITION_NONE（此處解決刷新問(wèn)題）
3叫胁、程序中實(shí)現(xiàn)數(shù)據(jù)源凰慈、viewpager及其adapter配置即可
代碼如下：
1、新建類(lèi)并繼承Fragment驼鹅，接受數(shù)據(jù)完善布局

public class MyFragment extends Fragment {

    public static Fragment newInstance(String content) {
        MyFragment fragment = new MyFragment();
        Bundle bundle = new Bundle();
        bundle.putString("content", content);
        fragment.setArguments(bundle);
        return fragment;
    }

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        String content = getArguments().getString("content");
        View view = inflater.inflate(R.layout.fragment_base, container, false);
        TextView textView = (TextView) view.findViewById(R.id.tvContent);
        textView.setText(content);
        return view;
    }
}

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/tvContent"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:textSize="20sp"
        android:textColor="@color/colorAccent"/>
</RelativeLayout>

2微谓、創(chuàng)建類(lèi)并繼承 FragmentStatePagerAdapter ，重寫(xiě)其內(nèi)部方法
3输钩、程序中實(shí)現(xiàn)數(shù)據(jù)源豺型、viewpager及其adapter配置即可

public class MainActivity extends AppCompatActivity implements View.OnClickListener{

    private List<String> contents = new ArrayList<>();
    private MyFragmentPagerAdapter adapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        contents.add("one");
        contents.add("two");
        contents.add("three");

        ViewPager viewPager = (ViewPager) findViewById(R.id.viewPager);
        Button add = (Button) findViewById(R.id.btnAdd);
        Button delete = (Button) findViewById(R.id.btnDelete);
        adapter = new MyFragmentPagerAdapter(getSupportFragmentManager());
        viewPager.setAdapter(adapter);

        add.setOnClickListener(this);
        delete.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btnAdd:
                contents.add("add");
                adapter.notifyDataSetChanged();
                break;
            case R.id.btnDelete:
                if (contents.size() > 0) {
                    contents.remove(contents.size() - 1);
                    adapter.notifyDataSetChanged();
                }
                break;
            default:
                break;
        }
    }

    class MyFragmentPagerAdapter extends FragmentStatePagerAdapter{

        private MyFragmentPagerAdapter(FragmentManager fm) {
            super(fm);
        }

        @Override
        public Fragment getItem(int position) {
            return MyFragment.newInstance(contents.get(position));
        }

        @Override
        public int getCount() {
            return contents.size();
        }

        @Override
        public int getItemPosition(Object object) {
            return PagerAdapter.POSITION_NONE;
        }
    }
}

Kotlin代碼如下

class MyFragment : Fragment() {

    fun newInstance(text:String):MyFragment{
        val fragment = MyFragment()
        val bundle = Bundle()
        bundle.putString("content", text)
        fragment.arguments = bundle
        return fragment
    }

    override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?, savedInstanceState: Bundle?): View {
        val content = arguments.getString("content")

        val view = inflater!!.inflate(R.layout.fragment_base, container, false)
        val tvContent: TextView = view.tvContent
        tvContent.text = content
        return view
    }

}

class MainActivity : AppCompatActivity() {

    val list = mutableListOf<String>("one", "two", "three")


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val adapter = MyFragmentPagerAdapter(supportFragmentManager, list)
        viewPager.adapter = adapter

        add.setOnClickListener {
            list.add("add")
            adapter.notifyDataSetChanged()
        }

        delete.setOnClickListener {
            if (list.size > 0) {
                list.removeAt(list.size-1)
                adapter.notifyDataSetChanged()
            }
        }

    }

    class MyFragmentPagerAdapter(fm:FragmentManager,val list: List<String>) : FragmentStatePagerAdapter(fm){

        /**
         * Return the Fragment associated with a specified position.
         */
        override fun getItem(position: Int): Fragment {
            return MyFragment().newInstance(list[position])
        }

        /**
         * Return the number of views available.
         */
        override fun getCount(): Int {
            return list.size
        }

        /**
         * 必須重寫(xiě)此方法才能完全刷新
         */
        override fun getItemPosition(`object`: Any?): Int {
            return PagerAdapter.POSITION_NONE
        }
    }
}

還有一種處理情況繼承的是 FragmentPagerAdapter時(shí)：
在Adapter中添加一個(gè)方法，手動(dòng)移除存在的Fragment

private void setFragments(List<OverlapFragment> fragments) {
            FragmentManager fm = getFragmentManager();

            if (mFragments != null) {
                FragmentTransaction ft = fm.beginTransaction();
                for (Fragment f : fragments) {
                    ft.remove(f);
                }
                ft.commit();
                ft = null;
                fm.executePendingTransactions();
            }
            mFragments = fragments;
            notifyDataSetChanged();
        }

贈(zèng)人玫瑰买乃，手有余香姻氨。您的支持是我創(chuàng)作最大的動(dòng)力!