android实现无限轮播，android实现轮播

android实现无限轮播，android实现轮播

1 在ViewPager的适配器中的getCount()长度设置无限大Integer.MAX_VALUE

2  明白当前currentIten 为position % images.length;

3  设置一开始ViewPager的位置 viewPager.setCurrentItem((images.length) * 1000);这样刚开始就可以向左滑动了

4  在OnPageChangeListener ViewPager的滑动监听中设置小点的位置

5  设置Handler 定时滑动开启滑动

6 在onResume中发送空消息，在onPause中移除消息将所有的Callbacks和Messages全部清除掉，避免内存泄露。

如下是主代码 图片是本地的

  1 package com.demo.sb.main;
  2 
  3 import java.util.ArrayList;
  4 import com.demo.sb.utils.DensityUtil;
  5 import com.demo.suibian.R;
  6 import android.annotation.SuppressLint;
  7 import android.app.Activity;
  8 import android.os.Bundle;
  9 import android.os.Handler;
 10 import android.support.v4.view.PagerAdapter;
 11 import android.support.v4.view.ViewPager;
 12 import android.support.v4.view.ViewPager.OnPageChangeListener;
 13 import android.view.MotionEvent;
 14 import android.view.View;
 15 import android.view.View.OnClickListener;
 16 import android.view.View.OnTouchListener;
 17 import android.view.ViewGroup;
 18 import android.widget.ImageView;
 19 import android.widget.LinearLayout;
 20 
 21 public class MActivity_Luenbo extends Activity {
 22 
 23     private ViewPager viewPager;
 24     private LinearLayout group;
 25     private int[] images = { R.drawable.a, R.drawable.c, R.drawable.d,
 26             R.drawable.guide_1, R.drawable.guide_2 };
 27     private ArrayList<ImageView> mImageViewList;
 28     private ImageView[] diandian;// ViewPager上的点点
 29     private int selectedItem = 0;
 30 
 31     @Override
 32     protected void onCreate(Bundle savedInstanceState) {
 33         // TODO Auto-generated method stub
 34         super.onCreate(savedInstanceState);
 35         setContentView(R.layout.mactivity_luenbo);
 36         viewPager = (ViewPager) findViewById(R.id.vp_viewPager);
 37         group = (LinearLayout) findViewById(R.id.ll_viewGroup);
 38         init();
 39 
 40     }
 41 
 42     @SuppressLint("HandlerLeak")
 43     private Handler mHandler = new Handler() {
 44         public void handleMessage(android.os.Message msg) {
 45             viewPager.setCurrentItem(selectedItem + 1);
 46             mHandler.sendEmptyMessageDelayed(0, 3000);
 47         };
 48     };
 49 
 50     private void init() {
 51         // TODO Auto-generated method stub
 52         // 引导3个ViewPager
 53         mImageViewList = new ArrayList<ImageView>();
 54         for (int i = 0; i < images.length; i++) {
 55             ImageView imageView = new ImageView(this);
 56             imageView.setBackgroundResource(images[i]);
 57             mImageViewList.add(imageView);
 58         }
 59 
 60         // 将点点加入到ViewGroup中
 61         diandian = new ImageView[images.length];
 62         for (int i = 0; i < images.length; i++) {
 63             // 循环加入点点图片组
 64             diandian[i] = new ImageView(this);
 65             if (i == 0) {
 66                 diandian[i].setImageResource(R.drawable.page_indicator_focused);
 67             } else {
 68                 diandian[i]
 69                         .setImageResource(R.drawable.page_indicator_unfocused);
 70             }
 71             diandian[i].setPadding(8, 8, 8, 8);
 72             group.addView(diandian[i]);
 73         }
 74         viewPager.setAdapter(new GuideAdapter());
 75         // 设置监听，主要是设置点点的背景
 76         viewPager.setOnPageChangeListener(new GuidePagerListener());
 77         // 设置ViewPager的默认项，设置为长度的1000倍，这样开始就能向左滑动了
 78         viewPager.setCurrentItem((images.length) * 1000);
 79     }
 80 
 81     /**
 82      * 每次当onResume有焦点时发送个空消息开始轮播
 83      */
 84     @Override
 85     protected void onResume() {
 86         // TODO Auto-generated method stub
 87         super.onResume();
 88         mHandler.sendEmptyMessageDelayed(0, 2000);
 89     }
 90 
 91     /**
 92      * 当暂停时停止轮播
 93      */
 94     @Override
 95     protected void onPause() {
 96         // TODO Auto-generated method stub
 97         super.onPause();
 98         mHandler.removeCallbacksAndMessages(null);
 99     }
100 
101     /**
102      * ViewPager的适配器
103      * 
104      */
105     private class GuideAdapter extends PagerAdapter {
106 
<