ViewPager无限轮播

activity_main

xml version="1.0" encoding="utf-8"?>
<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="animtest.com.example.e531.zixun_tostudent.MainActivity">

<android.support.v4.view.ViewPager
    android:layout_width="match_parent"
    android:layout_height="200dp"
    android:id="@+id/vp">android.support.v4.view.ViewPager>


<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:id="@+id/lin_bottom"
    android:layout_alignBottom="@+id/vp"
    android:gravity="center"
    android:layout_marginBottom="7dp">LinearLayout>


RelativeLayout>

point_selected

 xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="oval">
	<solid android:color="#f00">solid>

shape>

point_un_selected


xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="oval">
	<solid android:color="#ccc">solid>

shape>

ImageloaderUtil


package animtest.com.example.e531.zixun_tostudent;

        import android.content.Context;
        import android.graphics.Bitmap;
        import android.os.Environment;

        import com.nostra13.universalimageloader.cache.disc.impl.UnlimitedDiscCache;
        import com.nostra13.universalimageloader.cache.disc.naming.Md5FileNameGenerator;
        import com.nostra13.universalimageloader.core.DisplayImageOptions;
        import com.nostra13.universalimageloader.core.ImageLoader;
        import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;

        import java.io.File;

/**
 *
 */
public class ImageloaderUtil {
    /**
     * ImageLoader的配置
     * @param context
     */
    public static void initConfig(Context context) {
        //配置
//        File cacheFile=context.getExternalCacheDir();
       File cacheFile= new File(Environment.getExternalStorageDirectory()+"/"+"imgages");

        ImageLoaderConfiguration config=new ImageLoaderConfiguration.Builder(context)
                .memoryCacheExtraOptions(480, 800)//缓存图片最大的长和宽
                .threadPoolSize(2)//线程池的数量
                .threadPriority(4)
                .memoryCacheSize(2*1024*1024)//设置内存缓存区大小
                .diskCacheSize(20*1024*1024)//设置sd卡缓存区大小
                .diskCache(new UnlimitedDiscCache(cacheFile))//自定义缓存目录
                .writeDebugLogs()//打印日志内容
                .diskCacheFileNameGenerator(new Md5FileNameGenerator())//给缓存的文件名进行md5加密处理
                .build();

        ImageLoader.getInstance().init(config);
    }

    /**
     * 获取图片设置类
     * @return
     */
    public static DisplayImageOptions getImageOptions(){

        DisplayImageOptions optionsoptions=new DisplayImageOptions.Builder()
                .cacheInMemory(true)//使用内存缓存
                .cacheOnDisk(true)//使用磁盘缓存
                .bitmapConfig(Bitmap.Config.RGB_565)//设置图片格式
                .build();

        return optionsoptions;
    }
}


MyApplication

package animtest.com.example.e531.zixun_tostudent;

        import android.app.Application;

        import com.nostra13.universalimageloader.cache.disc.impl.UnlimitedDiscCache;
        import com.nostra13.universalimageloader.cache.disc.naming.Md5FileNameGenerator;
        import com.nostra13.universalimageloader.core.ImageLoader;
        import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;

        import java.io.File;

/**
 * Created by e531 on 2017/10/14.
 */
public class MyApplication extends Application {
    @Override
    public void onCreate() {
        super.onCreate();

        //进行全局初使化
        ImageloaderUtil.initConfig(this);
    }
}


ImagePager

package animtest.com.example.e531.zixun_tostudent;

        import android.content.Context;
        import android.os.Handler;
        import android.support.v4.view.PagerAdapter;
        import android.util.Log;
        import android.view.MotionEvent;
        import android.view.View;
        import android.view.ViewGroup;
        import android.widget.ImageView;
        import android.widget.Toast;

        import com.nostra13.universalimageloader.core.ImageLoader;

        import java.util.List;

/**
 */
public class ImagePager extends PagerAdapter {
    Context context;
    List list;//网络图片地址


    public ImagePager(Context context, List list) {
        this.context = context;
        this.list = list;
    }

    //返回页面的数量
    @Override
    public int getCount() {
        return Integer.MAX_VALUE;
    }

    @Override
    public boolean isViewFromObject(View view, Object object) {
        return view==object;
    }

    //0~getCount返回的值-1
    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        //返回当前显示的视图
        ImageView imageView = new ImageView(context);
        imageView.setScaleType(ImageView.ScaleType.FIT_XY);

        //加载网络的图片list.get(position%list.size())
        ImageLoader.getInstance().displayImage(list.get(position%list.size()),imageView,ImageloaderUtil.getImageOptions());


        //添加到容器
        container.addView(imageView);

        return imageView;
    }

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

        container.removeView((View) object);
    }
}


MainActivity

package animtest.com.example.e531.zixun_tostudent;

        import android.os.Handler;
        import android.os.Message;
        import android.support.v4.view.ViewPager;
        import android.support.v7.app.AppCompatActivity;
        import android.os.Bundle;
        import android.widget.ImageView;
        import android.widget.LinearLayout;
        import java.util.ArrayList;
        import java.util.List;

/**
 *
 * ViewPager 自动无限轮播-前不见头 后不见尾,handler
 *
 * 适配器PagerAdapter
 * 1.getCount:Interger.max_value无限大
 * 2.insta...Item:装载页面   1.加载页面的视图 2.返回一个object
 *               动态生成页面
 *
 * 3.destroy...item:销毁页面 去掉super.des... 移除remove(view)
 * 3.isViewfromObject: arg1==arg0
 *
 * viewpager默认是加载三页
 * 设置当前显示的页面  setCurrentItem(0)
 *
 * ImageLoader异步获取图片
 *
 */
public class MainActivity extends AppCompatActivity {

    private ViewPager viewPager;
    private List list;
    private LinearLayout linearLayout;
    //存放小圆点控件的集合
    private List images;

    private Handler myHandler=new Handler(){
        @Override
        public void handleMessage(Message msg) {
            //获取当前正在显示的页面
            int index=viewPager.getCurrentItem();
            viewPager.setCurrentItem(index+1);
            //改变小圆点
            setSelectedPoint((index+1)%list.size());
            //延迟发送消息
            sendEmptyMessageDelayed(1,2000);
        }
    };

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

        viewPager = (ViewPager) findViewById(R.id.vp);
        linearLayout = (LinearLayout) findViewById(R.id.lin_bottom);

        //数据.....装的是path路径
        list = new ArrayList<>();
        list.add("https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1505151721118&di=649c9a43aed72fbc4d99ec1a031510c6&imgtype=0&src=http%3A%2F%2Fimg.zcool.cn%2Fcommunity%2F015c7d574b9f8f6ac72525aee98351.jpg");
        list.add("https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1505151956771&di=0eb6f306991d24b67a13ceb336f80102&imgtype=0&src=http%3A%2F%2Fi0.hdslb.com%2Fbfs%2Farchive%2F00613def3f1beb7a35ae136341be2b589bc46a2d.jpg_320x200.jpg");
        list.add("https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1505151847685&di=c7a4b5d08ec43fa629bcb690039a7629&imgtype=0&src=http%3A%2F%2Fattimg.dospy.com%2Fimg%2Fday_080625%2F20080625_2e91a10c444877e88827vri2ZKdGMvQo.jpg");
        list.add("https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1505151825129&di=70bf74b87d8a15cb91a2d79f15ed0eaf&imgtype=0&src=http%3A%2F%2Fattimg.dospy.com%2Fimg%2Fday_081016%2F20081016_fee215664d5740e56c13E2YB8giERFEX.jpg");
        list.add("https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1505746504&di=930c4d677a02328a142d6fa85ed14580&imgtype=jpg&er=1&src=http%3A%2F%2Fattimg.dospy.com%2Fimg%2Fday_090113%2F20090113_6ac58b42bea94f0b318e1B6BZb5lPZl5.jpg");

        //初始化小圆点
        initDoc();

        //设置适配器
        viewPager.setAdapter(new ImagePager(this,list));

        //设置当前要显示的页面
        viewPager.setCurrentItem(list.size()*10);

        //实现自动播放
        myHandler.sendEmptyMessageDelayed(1,2000);
    }

    /**
     * 改变小圆点图片
     * @param index  页面的下标
     */
    public  void setSelectedPoint(int index){
        for(int i=0;i<images.size();i++){
            if(i==index){
                images.get(i).setImageResource(R.drawable.point_selected);
            }else{
                images.get(i).setImageResource(R.drawable.point_un_selected);
            }
        }
    }

    /**
     * 初始化小圆点
     * 动态添加
     */
    private void initDoc() {
        images=new ArrayList<>();

        for(int i=0;i<list.size();i++){
            ImageView imgPoint=new ImageView(this);
            //设置图片的缩放模式
            imgPoint.setScaleType(ImageView.ScaleType.FIT_XY);
            //设置要显示的图片
            if(i==0){
                //红色的点
                imgPoint.setImageResource(R.drawable.point_selected);
            }else{
                imgPoint.setImageResource(R.drawable.point_un_selected);
            }

            //设置宽度与高度
            LinearLayout.LayoutParams  params=new LinearLayout.LayoutParams(40,40);
            params.setMargins(10,0,10,0);
            //添加到底部容器中
            linearLayout.addView(imgPoint,params);
            //添加到集合中
            images.add(imgPoint);

        }
    }
}



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