使用ViewPager实现自动轮播+小圆点

/*

 *activity_main

*/

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

<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="6">

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

<LinearLayout
android:id="@+id/dotContainer"
android:layout_width="match_parent"
android:layout_height="40dp"
android:layout_alignParentBottom="true"
android:gravity="center"
android:orientation="horizontal" />

</RelativeLayout>

<ListView
android:id="@+id/lv"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="4" />

</LinearLayout>

 *doc_select

*/

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<size
android:width="10dp"
android:height="10dp" />
<solid
android:color="#ff0000"/>
<corners
android:radius="5dp"/>
</shape>

/*

 *doc_select_no

*/

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<size
android:width="10dp"
android:height="10dp" />
<solid
android:color="#00ff00"/>

<corners
android:radius="5dp"/>
</shape>

/*

 *MainActivity

*/

import android.os.AsyncTask;
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 com.bawei.adapter.MyPagerAdapter;
import com.bawei.bean.NewsListBean;
import com.bawei.bean.SuperClass;
import com.bawei.utils.NetWorkUtil;
import com.bawei.utils.URLDB;
import com.google.gson.Gson;

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

public class MainActivity extends AppCompatActivity {

    private ViewPager viewPager;
    private LinearLayout dotContainer;
    private NetWorkUtil netWorkUtil;
    private List<String> list;
    private Handler handler = new Handler(){
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            if (msg.what == 0){
                int currentItem = viewPager.getCurrentItem();
                viewPager.setCurrentItem(currentItem+1);
                handler.sendEmptyMessageDelayed(0,2000);
            }
        }
    };
    private List<ImageView> imgList;

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

    private void init() {
        viewPager = (ViewPager) findViewById(R.id.viewPager);
        dotContainer = (LinearLayout) findViewById(R.id.dotCantainer);
        netWorkUtil = new NetWorkUtil();
        new AsyncTask<String,Integer,String>(){

            @Override
            protected String doInBackground(String... params) {
                String param = params[0];
                String jsonStr = netWorkUtil.getJsonHttpURLConnectionGet(param);
                return jsonStr;
            }

            @Override
            protected void onPostExecute(String s) {
                super.onPostExecute(s);
                //解析数据
                SuperClass superClass = new Gson().fromJson(s, SuperClass.class);
                List<NewsListBean> newslist = superClass.getNewslist();
                list = new ArrayList<String>();
                for (int i=0;i<newslist.size();i++){
                    list.add(newslist.get(i).getPicUrl());
                }
                //初始化小圆点
                initDoc();

                MyPagerAdapter myPagerAdapter = new MyPagerAdapter(MainActivity.this,list);
                viewPager.setAdapter(myPagerAdapter);
                viewPager.setCurrentItem(list.size()*10000);
                handler.sendEmptyMessageDelayed(0,2000);

                viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
                    @Override
                    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

                    }

                    @Override
                    public void onPageSelected(int position) {
                        for (int i=0;i<imgList.size();i++){
                            if (i == position%imgList.size()){
                                imgList.get(i).setImageResource(R.drawable.doc_select);
                            }else {
                                imgList.get(i).setImageResource(R.drawable.doc_select_no);
                            }
                        }
                    }

                    @Override
                    public void onPageScrollStateChanged(int state) {

                    }
                });
            }

        }.execute(URLDB.JSON_URL);
    }

    private void initDoc() {
        imgList = new ArrayList<>();
        dotContainer.removeAllViews();

        for (int i=0;i<list.size();i++){
            ImageView imageView = new ImageView(MainActivity.this);
            if (i == 0){
                imageView.setImageResource(R.drawable.doc_select);
            }else {
                imageView.setImageResource(R.drawable.doc_select_no);
            }
            //添加到集合
            imgList.add(imageView);
            //添加到线性布局
            LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,LinearLayout.LayoutParams.WRAP_CONTENT);
            params.setMargins(5,0,5,0);
            dotContainer.addView(imageView,params);
        }
    }
}

/*

*MyPagerAdapter

*/

package com.bawei.adapter;

import android.content.Context;
import android.support.v4.view.PagerAdapter;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;

import com.nostra13.universalimageloader.core.ImageLoader;

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

/**
* Created by dell on 2017-09-12.
*/

public class MyPagerAdapter extends PagerAdapter{
private Context context;
private List<String> list;

public MyPagerAdapter(Context context, List<String> list) {
this.context = context;
this.list = list;
}

@Override
public int getCount() {
return Integer.MAX_VALUE;
}

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

@Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((View) object);
}

@Override
public Object instantiateItem(ViewGroup container, int position) {
//创建ImageView对象
ImageView img = new ImageView(context);
img.setScaleType(ImageView.ScaleType.FIT_XY);
//加载图片
ImageLoader.getInstance().displayImage(list.get(position%list.size()),img);
container.addView(img);
return img;
}
}

/*

*MyApplication

*/

package com.bawei.mapp;

import android.app.Application;

import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;

/**
* Created by dell on 2017-09-12.
*/

public class MyApplication extends Application{
@Override
public void onCreate() {
super.onCreate();
ImageLoaderConfiguration configuration = new ImageLoaderConfiguration.Builder(this)
.memoryCacheExtraOptions(200,400)
.build();
ImageLoader.getInstance().init(configuration);
}
}