ActionBar+ViewPager+Fragment实现滑动效果

在上个博客里我们已经知道了怎么点击来切换fragment这次我们要在此基础实现滑动的效果,感觉加上viewpager更简单了,

首先viewpager需要一个适配器,我们就自定义一个适配器并且继承FragmentPagerAdapter;

//自定义一个适配器继承FragmentPagerAdapter
    class ViewPagerAdapter extends FragmentPagerAdapter {

        public ViewPagerAdapter(FragmentManager fm) {
            super(fm);
            // TODO Auto-generated constructor stub
        }
        //返回的Fragment
        @Override
        public Fragment getItem(int item) {
            //声明一个Fragment
       Fragment f = null;
            switch (item) {
            case 0:
                f = new TicketsFragment();
                break;
            case 1:
                f = new OrderFragment();
                break;
            case 2:
                f = new MyFragment();
                break;
            }
            return f;
        }
        //Fragment总数
        @Override
        public int getCount() {
            // TODO Auto-generated method stub
            return 3;
        }
    }

然后把pager和adapter进行绑定,并且设置改变的监听事件

      pager.setAdapter(new ViewPagerAdapter(getSupportFragmentManager()));
        pager.setOnPageChangeListener(new OnPageChangeListener() {
            
            @Override
            public void onPageSelected(int arg0) {
                // TODO Auto-generated method stub
               //设置标签的改变 
          bar.setSelectedNavigationItem(arg0); } @Override
public void onPageScrolled(int arg0, float arg1, int arg2) { // TODO Auto-generated method stub } @Override public void onPageScrollStateChanged(int arg0) { // TODO Auto-generated method stub } });

这时候我们还需要做件事情  就是滑动是在pager里,而点击标签是在布局之下,这两个不统一。我们要以viwepager为主,那我们怎么来修改呢?
首先我们要把TabListener这个实现类里改变页面不在变布局下,而是改变viewpager,这时候我们也不用传递参数了

class MyTabListenerImpl implements TabListener {
    

        @Override
        // 选中标签
        public void onTabSelected(Tab tab, FragmentTransaction ft) {
            // TODO Auto-generated method stub
            //设置当前显示的位置
            pager.setCurrentItem(tab.getPosition());
        }

        @Override
        // 没有选中标签
        public void onTabUnselected(Tab tab, FragmentTransaction ft) {
            // TODO Auto-generated method stub
            
        }

        @Override
        // 重新选中标签
        public void onTabReselected(Tab tab, FragmentTransaction ft) {
            // TODO Auto-generated method stub

        }

    }

这时候就完成了

布局代码

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/layoutmain"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

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

</RelativeLayout>

activity

package com.example.my12306;

import android.os.Bundle;
import android.app.ActionBar;
import android.app.ActionBar.TabListener;
import android.app.Activity;
import android.app.FragmentTransaction;
import android.app.ActionBar.Tab;

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.view.Menu;

public class PeopleActivity extends FragmentActivity {
    private ViewPager pager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_people);
        final ActionBar bar = getActionBar();
        bar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
        // 不显示标题
        bar.setDisplayShowTitleEnabled(false);
        pager = (ViewPager) findViewById(R.id.pager);
        pager.setAdapter(new ViewPagerAdapter(getSupportFragmentManager()));
        pager.setOnPageChangeListener(new OnPageChangeListener() {
            
            @Override
            public void onPageSelected(int arg0) {
                // TODO Auto-generated method stub
                bar.setSelectedNavigationItem(arg0);
            }
            
            @Override
            public void onPageScrolled(int arg0, float arg1, int arg2) {
                // TODO Auto-generated method stub
                
            }
            
            @Override
            public void onPageScrollStateChanged(int arg0) {
                // TODO Auto-generated method stub
                
            }
        });


        
        //添加的过程一定要放在viewpager之后
        bar.addTab(bar
                .newTab()
                .setText("车票预订")
                .setTabListener(
                        new MyTabListenerImpl()));
        bar.addTab(bar
                .newTab()
                .setText("订单查询")
                .setTabListener(
                        new MyTabListenerImpl()));
        bar.addTab(bar
                .newTab()
                .setText("@我的")
                .setTabListener(
                        new MyTabListenerImpl()));

    }

    class MyTabListenerImpl implements TabListener {
    

        @Override
        // 选中标签
        public void onTabSelected(Tab tab, FragmentTransaction ft) {
            // TODO Auto-generated method stub
            //设置当前显示的位置
            pager.setCurrentItem(tab.getPosition());
        }

        @Override
        // 没有选中标签
        public void onTabUnselected(Tab tab, FragmentTransaction ft) {
            // TODO Auto-generated method stub
            
        }

        @Override
        // 重新选中标签
        public void onTabReselected(Tab tab, FragmentTransaction ft) {
            // TODO Auto-generated method stub

        }

    }
    //自定义一个适配器继承FragmentPagerAdapter
    class ViewPagerAdapter extends FragmentPagerAdapter {

        public ViewPagerAdapter(FragmentManager fm) {
            super(fm);
            // TODO Auto-generated constructor stub
        }
        //返回的Fragment
        @Override
        public Fragment getItem(int item) {
            Fragment f = null;
            //判断是第几页然后new 出来传回去
            switch (item) {
            case 0:
                f = new TicketsFragment();
                break;
            case 1:
                f = new OrderFragment();
                break;
            case 2:
                f = new MyFragment();
                break;
            }
            return f;
        }
        //Fragment总数
        @Override
        public int getCount() {
            // TODO Auto-generated method stub
            return 3;
        }

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.people, menu);
        return true;
    }

}
原文地址:https://www.cnblogs.com/84126858jmz/p/4909051.html