Android——用FragmentPagerAdapter实现Fragment的滑动效果

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.chenshuai.test322.Activityad">

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

        <!--PagerTitleStrip加标题-->
        <android.support.v4.view.PagerTitleStrip
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

        </android.support.v4.view.PagerTitleStrip>

    </android.support.v4.view.ViewPager>

</LinearLayout>

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


    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/coco"
        />

</LinearLayout>

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

    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/df"
       />

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/hh"
        />



</LinearLayout>

package com.example.chenshuai.test322;

import android.content.Context;
import android.os.Bundle;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import java.util.ArrayList;
import java.util.List;

public class Activityad extends AppCompatActivity {

    private ViewPager viewPager;
    private List<View> content;
    private LayoutInflater inflater;
    private List<String> title;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_activityad);

        viewPager = (ViewPager)findViewById(R.id.viewpage);

        //准备数据
        content = new ArrayList<View>();
        //inflater = LayoutInflater.from(this);
        inflater = getLayoutInflater();
        /**
         * 添加内容content
         */

        content.add(inflater.inflate(R.layout.layout_ad1,null));
        content.add(inflater.inflate(R.layout.layout_ad2,null));
        content.add(inflater.inflate(R.layout.layout_ad3,null));

        /**
         * 添加每个内容对应的标题title
         */
        title = new ArrayList<String>();
        title.add("体育新闻");
        title.add("娱乐新闻");
        title.add("军事新闻");

        viewPager.setAdapter(new viewadapter(this,content,title));

    }

    public class viewadapter extends PagerAdapter
    {
        private Context context;
        private List<View> content;
        private List<String> title;

        //重写构造方法，加图片，加标题
        public viewadapter(Context context, List<View> content,
                                  List<String> title) {
            this.context = context;
            this.content = content;
            this.title = title;
        }
        // 必须 1- 获取要滑动的控件的数量，在这里我们以滑动的广告栏为例，那么这里就应该是展示的广告图片的ImageView数量
        @Override
        public int getCount() {
            return content.size();
        }

        //实现标题的方法
        @Override
        public CharSequence getPageTitle(int position) {

            return  title.get(position);
        }

        //必须 2-  来判断显示的是否是同一张图片，这里我们将两个参数相比较返回即可
        @Override
        public boolean isViewFromObject(View view, Object object) {
            return view == object;
        }

        //必须 3-  PagerAdapter只缓存三张要显示的图片，如果滑动的图片超出了缓存的范围，就会调用这个方法，将图片销毁

        @Override
        public void destroyItem(ViewGroup container, int position, Object object) {

            ((ViewPager)container).removeView(content.get(position));
            //super.destroyItem(container, position, object);
        }

        //必须 4- // 当要显示的图片可以进行缓存的时候，会调用这个方法进行显示图片的初始化，
        // 我们将要显示的ImageView加入到ViewGroup中，然后作为返回值返回即可
        @Override
        public Object instantiateItem(ViewGroup container, int position) {

            ((ViewPager)container).addView(content.get(position));
            return  content.get(position);
        }
    }
}