Android自动播放图片功能实现

第一种方式:回退到第一张

效果图

第二种方式:无限循环

效果图:

源代码

逻辑代码--MainActivity

<span style="font-family:Comic Sans MS;font-size:18px;">package com.example.week4_day4_viewpager2;import java.util.ArrayList;import java.util.List;import android.R.integer;import android.os.Bundle;import android.os.Handler;import android.app.Activity;import android.support.v4.view.ViewPager;import android.view.Menu;import android.widget.ImageView;public class MainActivity extends Activity {private ViewPager viewPager;// 数据源private int[] images = { R.drawable.image1, R.drawable.image2,R.drawable.image3 };// 存放数据源的集合List<ImageView> list;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);viewPager = (ViewPager) findViewById(R.id.viewpager);// 实例化listlist = new ArrayList<ImageView>();for (int i = 0; i < images.length; i++) {ImageView imageView = new ImageView(MainActivity.this);imageView.setImageResource(images[i]);list.add(imageView);}// 绑定适配器viewPager.setAdapter(new MyViewPagerAdapter(MainActivity.this, list));// 当有3张图片时,走到id=2时最后一张,viewPager.setCurrentItem(Integer.MAX_VALUE / 2 - Integer.MAX_VALUE / 2% list.size());// 假设viewPager有无数条数据// 延迟两秒发送一条消息handler.sendEmptyMessageDelayed(1, 2000);}// 让图片自动播放,无限循环private Handler handler = new Handler() {public void handleMessage(android.os.Message msg) {/** * 第一种方法,播放到最后一张时,回退到第一张照片从头播放 * 弊端:回退时如果图片过多,会出现回退重影,即3张时,从最后一张瞬间回退到第2张,又瞬间回退到第1张 */// int i = viewPager.getCurrentItem();// 当前item// if (i == list.size() - 1) {// 如果第一条等于最后一条// // false:是否显示动画// viewPager.setCurrentItem(0, true);// 回到第一条item// } else {// viewPager.setCurrentItem(i + 1, true);// }/** * 第二种方法,无限循环播放,每次都把所有相片,放到后面查看 */viewPager.setCurrentItem(viewPager.getCurrentItem() + 1);sendEmptyMessageDelayed(1, 2000);};};}</span>

逻辑代码--自定义适配器

<span style="font-family:Comic Sans MS;font-size:18px;">package com.example.week4_day4_viewpager2;import java.util.List;import android.content.Context;import android.support.v4.view.PagerAdapter;import android.view.View;import android.view.ViewGroup;import android.widget.ImageView;public class MyViewPagerAdapter extends PagerAdapter{private Context context;private List<ImageView> list;public MyViewPagerAdapter(Context context, List<ImageView> list) {super();this.context = context;this.list = list;}@Overridepublic int getCount() {// TODO Auto-generated method stubreturn Integer.MAX_VALUE;//设置viewPager里有N条数据//return list.size();}@Overridepublic Object instantiateItem(ViewGroup container, int position) {//假设有3张照片,走到id=2时,走id=0的,所以取余container.addView(list.get(position%list.size()));return list.get(position%list.size());//return list.get(position);}@Overridepublic void destroyItem(ViewGroup container, int position, Object object) {// TODO Auto-generated method stubcontainer.removeView(list.get(position%list.size()));//container.removeView(list.get(position));//super.destroyItem(container, position, object);}@Overridepublic boolean isViewFromObject(View arg0, Object arg1) {// TODO Auto-generated method stubreturn arg0==arg1;}}</span>

布局文件

<span style="font-family:Comic Sans MS;font-size:18px;"><RelativeLayout 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=".MainActivity" >    <android.support.v4.view.ViewPager        android:id="@+id/viewpager"        android:layout_width="match_parent"        android:layout_height="match_parent"      /></RelativeLayout></span>