自定义无限轮播ViewPager的实现

1、RollViewPager：

import android.content.Context;
import android.os.Handler;
import android.os.Message;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import com.bumptech.glide.Glide;
import java.util.List;

public class RollViewPager extends ViewPager{
    private List<ImageView> mDots;//点的集合
    private List<String> mTitles;//标题数据集合
    private TextView tv_title;//显示标题的文本控件
    private List<String> mImages;//图片地址
    private RollAdapter mAdapter;
    private static final int MAX_COUNT = 10000000;
    private int currentPostion = MAX_COUNT / 2;//当前选中脚标
	private long mCurrentTimeMillis;//手指按下时的毫秒值
    private OnClickItemListener mOnClickItemListener;//点击事件接口回调
	
    private Handler mHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            //让viewpager切换下一个页面
            RollViewPager.this.setCurrentItem(currentPostion + 1,true);
            mHandler.sendEmptyMessageDelayed(0, 2000);
        }
    };

    public RollViewPager(Context context) {
        super(context);
        this.addOnPageChangeListener(new OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }
            @Override
            public void onPageSelected(int position) {
                //修改标题
                tv_title.setText(mTitles.get(position % mImages.size()));
                //修改对应点的选中状态
                mDots.get(currentPostion % mImages.size()).setImageResource(R.drawable.dot_normal);
                mDots.get(position % mImages.size()).setImageResource(R.drawable.dot_focus);
                currentPostion = position;
            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });

        this.setOnTouchListener(new OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                switch (event.getAction()) {
                    case MotionEvent.ACTION_DOWN:
                        //自动轮播停止
                        mHandler.removeCallbacksAndMessages(null);
                        mCurrentTimeMillis = System.currentTimeMillis();
                        break;
                    case MotionEvent.ACTION_UP:
                        //自动轮播开始
                        mHandler.sendEmptyMessageDelayed(0, 2000);
                        long upTime = System.currentTimeMillis();
                        if ((upTime - mCurrentTimeMillis) < 100) {//手指按下与手指抬起之间的时间间隔小于100ms则认为是点击事件
                            Toast.makeText(getContext(),"点击事件被响应了",Toast.LENGTH_SHORT).show();
                            mOnClickItemListener.onClick(currentPostion % mImages.size());
                        }
                        break;
                    case MotionEvent.ACTION_CANCEL:
                        mHandler.sendEmptyMessageDelayed(0, 2000);
                        break;
                }
                return false;
            }
        });
    }

    public RollViewPager(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public RollViewPager(MainActivity context, List<ImageView> dots, List<String> newsTitles, List<String> newsImages,TextView top_news_title) {
        this(context);
        this.mDots = dots;
        this.mTitles = newsTitles;
        this.mImages = newsImages;
        this.tv_title = top_news_title;
    }

    public void start() {
        //给轮播图设置适配器进行展示
        if (mAdapter == null) {
            mAdapter = new RollAdapter();
            this.setAdapter(mAdapter);
        } else {
            mAdapter.notifyDataSetChanged();
        }
        //让ViwPager的默认值改为Integer.MAX_VALUE/2
        this.setCurrentItem(currentPostion);
        //修改标题
        tv_title.setText(mTitles.get(currentPostion % mImages.size()));
        mDots.get(0).setImageResource(R.drawable.dot_normal);
        mDots.get(currentPostion % mImages.size()).setImageResource(R.drawable.dot_focus);
        //自动轮播
        mHandler.sendEmptyMessageDelayed(0, 2000);
    }

    private class RollAdapter extends PagerAdapter {
        @Override
        public int getCount() {
            return MAX_COUNT;
        }
        @Override
        public boolean isViewFromObject(View view, Object object) {
            return view == object;
        }
        @Override
        public Object instantiateItem(ViewGroup container, int position) {
            ImageView view = (ImageView) View.inflate(getContext(), R.layout.viewpager_item, null);
            Glide.with(getContext()).load(mImages.get(position % mImages.size())).into(view);
            container.addView(view);
            return view;
        }
        @Override
        public void destroyItem(ViewGroup container, int position, Object object) {
            container.removeView((View) object);
        }
    }

    public void setOnClickItemListener(OnClickItemListener listener) {
        this.mOnClickItemListener = listener;
    }

    //点击事件的接口
    public interface OnClickItemListener {
        public void onClick(int position);
    }
}

2、MainActivity

import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {

//  private List<NewItemBean.NewsItem> mNews = new ArrayList<>();//数据集合
    private List<String> mNewsTitles = new ArrayList<>();//标题
    private List<String> mNewsImages = new ArrayList<>();//图片地址url
    private List<ImageView> dots = new ArrayList<>();//小圆点集合
    private LinearLayout dots_ll;//用来展示小圆点的容器
    private TextView top_news_title;//用来展示轮播图的标题
    private LinearLayout top_news_viewpager;//用来展示轮播图的容器

    private Handler mHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            //轮播图控件
            RollViewPager rollViewPager = new RollViewPager(MainActivity.this,dots,mNewsTitles,mNewsImages,top_news_title);
            rollViewPager.setOnClickItemListener(new RollViewPager.OnClickItemListener() {
                @Override
                public void onClick(int position) {
                    Toast.makeText(MainActivity.this,"轮播图的点击" + position,Toast.LENGTH_SHORT).show();
                }
            });
            rollViewPager.start();
            //将轮播图rollviewpager添加到线性布局中进行展示
            top_news_viewpager.addView(rollViewPager);
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.layout_roll_view);
        dots_ll = (LinearLayout)findViewById(R.id.dots_ll);
        top_news_title = (TextView)findViewById(R.id.top_news_title);
        top_news_viewpager = (LinearLayout)findViewById(R.id.top_news_viewpager);
        initView()
	}
	
    private void initView() {
        //动态创建小圆点newItemBean.data.topnews.size(),这里写4
        initDots(4);
        //获取标题与图片数据
        mNewsTitles.clear();
        mNewsImages.clear();
        for (int i = 0; i < 4; i++) {
            mNewsTitles.add("标题" + (i + 1));
            mNewsImages.add("http://cn.bing.com/az/hprichbg/rb/Dongdaemun_ZH-CN10736487148_1920x1080.jpg");
        }
        mHandler.sendEmptyMessage(0);
    }
	
	//动态创建轮播图的点
    private void initDots(int size) {
        dots.clear();
        dots_ll.removeAllViews();
        for (int i = 0; i < size; i++) {
            ImageView dot = new ImageView(this);
            LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(DensityUtil.dip2px(this, 5), DensityUtil.dip2px(this, 5));
            if (i == 0) {
                dot.setImageResource(R.drawable.dot_focus);
            } else {
                dot.setImageResource(R.drawable.dot_normal);
                params.leftMargin = DensityUtil.dip2px(this, 5);
            }
            dot.setLayoutParams(params);
            dots.add(dot);
            //展示在界面上
            dots_ll.addView(dot);
        }
    }
}

3、布局

viewpager_item

<?xml version="1.0" encoding="utf-8"?>
<ImageView 
	xmlns:android="http://schemas.android.com/apk/res/android"
	android:id="@+id/image"
	android:layout_width="match_parent"
	android:layout_height="match_parent"
	android:background="@drawable/home_scroll_default"
	android:scaleType="fitXY"
	android:src="@drawable/home_scroll_default"
	>
</ImageView>

layout_roll_view

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
                android:layout_width="match_parent"
                android:layout_height="180dp"
    >

    <LinearLayout
        android:id="@+id/top_news_viewpager"
        android:layout_width="fill_parent"
        android:layout_height="185dp"
        android:orientation="horizontal"
        android:layout_alignParentTop="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"/>

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="30dp"
        android:layout_alignParentBottom="true"
        android:background="#88000000"
        android:gravity="center_vertical"
        android:orientation="horizontal">

        <TextView
            android:id="@+id/top_news_title"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginLeft="5dp"
            android:layout_marginRight="8dp"
            android:layout_weight="1"
            android:singleLine="true"
            android:text="图片标题"
            android:textColor="#F6F6F6"
            />

        <LinearLayout
            android:id="@+id/dots_ll"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginRight="5dp"
            android:gravity="center"
            android:orientation="horizontal"
            />
    </LinearLayout>
</RelativeLayout>