在綜合瀏覽量上添加新片段

Question

我想每次動態地向右滑動最后一個片段或向左滑動第一個片段時添加一個新片段。 該片段將添加到我的adapater中，並將其設置為我的viewPager。 現在，我在setupViewPager中定義了固定數量的片段，它們在OnCreate方法中“加載”。 這是我的代碼：

import android.content.Intent;
import android.os.Bundle;
import android.support.design.widget.NavigationView;
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.view.GravityCompat;
import android.support.v4.view.ViewPager;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.MenuItem;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;

import com.support.android.designlibdemo.Diafragment;
import com.support.android.designlibdemo.R;

import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.List;
import java.util.Locale;

public class MainActivity extends AppCompatActivity {

    private DrawerLayout mDrawerLayout;
    private ViewPager viewPager;

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

        Toolbar toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        viewPager = findViewById(R.id.viewpager);
        if (viewPager != null) {
            setupViewPager(viewPager);
        }

        Intent intent = getIntent();
        String nome = intent.getStringExtra("nome");

        View headerView = navigationView.getHeaderView(0);
        TextView navUsername = headerView.findViewById(R.id.tv_drawerUsername);
        navUsername.setText(nome);

        TabLayout tabLayout = findViewById(R.id.tabs);
        tabLayout.setupWithViewPager(viewPager);
    }

    private void setupViewPager(ViewPager viewPager) {

        SimpleDateFormat sdf = new SimpleDateFormat("EEE");
        Date date = new Date();
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        date = calendar.getTime();

        String day = sdf.format(date);

        Adapter adapter = new Adapter(getSupportFragmentManager());
        adapter.addFragment(new Diafragment(), day);

        calendar.add(Calendar.DATE, 1);
        date = calendar.getTime();
        String dayplusone = sdf.format(date);
        adapter.addFragment(new Diafragment(), dayplusone);

        calendar.add(Calendar.DATE, 1);
        date = calendar.getTime();
        String dayplustwo = sdf.format(date);
        adapter.addFragment(new Diafragment(), dayplustwo);

        viewPager.setAdapter(adapter);
    }


    static class Adapter extends FragmentPagerAdapter {
        private final List<Fragment> mFragments = new ArrayList<>();
        private final List<String> mFragmentTitles = new ArrayList<>();

        public Adapter(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);
        }
    }
}

Answer 1

只需擴展ViewPager並覆蓋onInterceptTouchEvent（）即可，如此處https://stackoverflow.com/a/13347008/2000083所示