【Android】viewpager banner 广告 自动轮播 小圆点

效果图：

1.首先自定义一个LinearLayout 

package com.i4evercai.bannerdemo.ui;

import java.util.ArrayList;
import java.util.List;
import java.util.Timer;
import java.util.TimerTask;

import android.app.Activity;
import android.content.Context;
import android.os.Handler;
import android.os.Message;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.view.LayoutInflater;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;

import com.i4evercai.bannerdemo.R;

public class BannerView extends LinearLayout {
	private ViewPager adViewPager;
	private ViewGroup group;
	private List<ImageView> bannerViewList = new ArrayList<ImageView>();
	private RelativeLayout pagerLayout;
	private int pageCount;
	private Timer bannerTimer;
	private Handler handler;
	private BannerTimerTask bannerTimerTask;
	public BannerView(Context context) {
		super(context);

	}

	public BannerView(Context context, AttributeSet attrs) {
		super(context, attrs);
		LayoutInflater inflater = (LayoutInflater) context
				.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
		inflater.inflate(R.layout.banner_view, this);
		initView(context);
		handler = new Handler() {
			public void handleMessage(Message msg) {
				adViewPager.setCurrentItem(msg.what);
				super.handleMessage(msg);

			}
		};
		bannerTimer = new Timer();
	}

	private void initView(final Context context) {
		RelativeLayout layout = (RelativeLayout) this
				.findViewById(R.id.view_pager_content);
		adViewPager = (ViewPager) this.findViewById(R.id.viewPager1);
		group = (ViewGroup) findViewById(R.id.iv_image);
		
		DisplayMetrics dm = new DisplayMetrics();
		((Activity) context).getWindowManager().getDefaultDisplay()
				.getMetrics(dm);
		LinearLayout.LayoutParams params = (LinearLayout.LayoutParams) layout
				.getLayoutParams();
		//根据图片高和宽的比例计算高度
		//测试图宽为694 高为323
		params.height = (int) (((double) dm.widthPixels / (double) 694 * (double) 323));
		layout.setLayoutParams(params);
	
		ImageView imageView;
		//初始化数据
		for (int i = 0; i < 8; i++) {
			imageView = new ImageView(context);
			imageView.setImageResource(R.drawable.banner);
			bannerViewList.add(imageView);
		}
		
		pageCount = bannerViewList.size();//对应小点个数
		final ImageView[] imageViews = new ImageView[pageCount];
		for (int i = 0; i < pageCount; i++) {
			LinearLayout.LayoutParams margin = new LinearLayout.LayoutParams(
					LinearLayout.LayoutParams.WRAP_CONTENT,
					LinearLayout.LayoutParams.WRAP_CONTENT);
			// 设置每个小圆点距离左边的间距
			margin.setMargins(10, 0, 0, 0);
			imageView = new ImageView(context);
			// 设置每个小圆点的宽高
			imageView.setLayoutParams(new LayoutParams(15, 15));
			imageViews[i] = imageView;
			if (i == 0) {
				// 默认选中第一张图片
				imageViews[i]
						.setBackgroundResource(R.drawable.page_indicator_focused);
			} else {
				// 其他图片都设置未选中状态
				imageViews[i]
						.setBackgroundResource(R.drawable.page_indicator_unfocused);
			}
			group.addView(imageViews[i], margin);
		}
		BannerViewAdapter adapter = new BannerViewAdapter(context,
				bannerViewList);
		adViewPager.setAdapter(adapter);
		adViewPager.setOnPageChangeListener(new OnPageChangeListener() {
			@Override
			public void onPageScrollStateChanged(int arg0) {
				// TODO Auto-generated method stub

			}

			@Override
			public void onPageScrolled(int arg0, float arg1, int arg2) {
				// TODO Auto-generated method stub
			}

			@Override
			public void onPageSelected(int arg0) {
				//当viewpager换页时 改掉下面对应的小点
				for (int i = 0; i < imageViews.length; i++) {
					//设置当前的对应的小点为选中状态
					imageViews[arg0]
							.setBackgroundResource(R.drawable.page_indicator_focused);
					if (arg0 != i) {
						//设置为非选中状态
						imageViews[i]
								.setBackgroundResource(R.drawable.page_indicator_unfocused);
					}
				}
			}

		});
	}


	//启动banner自动轮播
	public void bannerStartPlay(){
		if (bannerTimer != null) {
			if (bannerTimerTask != null)
				bannerTimerTask.cancel();
			bannerTimerTask = new BannerTimerTask();
			bannerTimer.schedule(bannerTimerTask, 5000, 5000);//5秒后执行，每隔5秒执行一次
		}
	}
	//暂停banner自动轮播
	public void bannerStopPlay(){
		if (bannerTimerTask != null)
			bannerTimerTask.cancel();
	}
	class BannerTimerTask extends TimerTask {
		@Override
		public void run() {
			// TODO Auto-generated method stub
			System.out.println("banner playing");
			Message msg = new Message();
			if (bannerViewList.size() <= 1)
				return;
			int currentIndex = adViewPager.getCurrentItem();
			if (currentIndex == bannerViewList.size() - 1)
				msg.what = 0;
			else
				msg.what = currentIndex + 1;

			handler.sendMessage(msg);
		}

	}
}

2.对应的adapter

package com.i4evercai.bannerdemo.ui;

import java.util.List;

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

public class BannerViewAdapter extends PagerAdapter {
	private List<ImageView> list;
	private Context context;
	
	public BannerViewAdapter(Context context, List<ImageView> list) {
		this.context = context;
		this.list = list;
	}

	@Override
	public int getCount() {
		// TODO Auto-generated method stub
		return list.size();
	}

	@Override
	public boolean isViewFromObject(View arg0, Object arg1) {
		// TODO Auto-generated method stub
		return arg0 == arg1;
	}

	public ImageView instantiateItem(View arg0, final int arg1) {
		((ViewPager) arg0).addView(list.get(arg1));
		list.get(arg1).setOnClickListener(new OnClickListener(){

			@Override
			public void onClick(View view) {
				// TODO Auto-generated method stub
				System.out.println("onClick:"+arg1);
			}
			
		});
		return list.get(arg1);
	}

	@Override
	public void destroyItem(View arg0, int arg1, Object arg2) {
		((ViewPager) arg0).removeView((View) arg2);
	}
}

3. 将自定义LinearLayout添加到布局里面

 <com.i4evercai.bannerdemo.ui.BannerView
        android:id="@+id/bannerview1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical" >
    </com.i4evercai.bannerdemo.ui.BannerView>

4.在activity里面实例对象

bannerView=(BannerView) findViewById(R.id.bannerview1);

5.在onResume() onPause()里面添加banner自动轮播开始和暂停

protected void onResume() {
		super.onResume();
		bannerView.bannerStartPlay();
	}

	@Override
	protected void onPause() {
		super.onPause();
		bannerView.bannerStopPlay();
	}

demo下载