ViewPager自动无限轮播加小圆点

最新推荐文章于 2018-06-08 11:19:22 发布

原创最新推荐文章于 2018-06-08 11:19:22 发布 · 452 阅读

0 ·

CC 4.0 BY-SA版权

本文介绍如何使用 Android 的 ViewPager 控件实现图片轮播效果，包括布局文件设置、代码实现及自定义适配器等关键步骤，并展示了如何通过 Handler 定时切换图片。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

1，布局

2，代码

public class MainActivity extends Activity {

   // 定义成员变量
   private ViewPager viewpager;
   private LinearLayout linear;

//定义图片的地址数组（图片可以从网上获取）

    int[] imageurl = new int[] { R.drawable.aaa, R.drawable.abcd, R.drawable.b,
           R.drawable.c, R.drawable.e };
   ArrayList<ImageView> iv_list = new ArrayList<ImageView>();

   Handler handler=new Handler(){
       public void handleMessage(android.os.Message msg) {
           int item=msg.what;
           item++;
           viewpager.setCurrentItem(item);
           handler.sendEmptyMessageDelayed(item, 2000);
       };
   };
   @Override
   protected void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_main);
       // 找控件
       viewpager = (ViewPager) findViewById(R.id.viewpager);
       linear = (LinearLayout) findViewById(R.id.linear);
       addLiner();

//ViewPager添加适配器

        viewpager.setAdapter(new PagerAdapter() {

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

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

           @Override
           public Object instantiateItem(ViewGroup container, int position) {
               // TODO Auto-generated method stub
               ImageView image = new ImageView(MainActivity.this);
               image.setImageResource(imageurl[position % imageurl.length]);
               container.addView(image);
               return image;
           }

           @Override
           public void destroyItem(ViewGroup container, int position,
                   Object object) {
               // TODO Auto-generated method stub
               // super.destroyItem(container, position, object);
               container.removeView((View) object);
           }
       });

//ViewPager页面轮播是的监听

        viewpager.setOnPageChangeListener(new OnPageChangeListener() {

           @Override
           public void onPageSelected(int arg0) {
               for(int i=0;i<iv_list.size();i++){
                   if(i==arg0%imageurl.length){
                       iv_list.get(i).setImageDrawable(getResources().getDrawable(R.drawable.format_and));
                   }else{
                       iv_list.get(i).setImageDrawable(getResources().getDrawable(R.drawable.format_normal));
                   }
               }
           }

           @Override
           public void onPageScrolled(int arg0, float arg1, int arg2) {

           }

           @Override
           public void onPageScrollStateChanged(int arg0) {

           }
       });
       handler.sendEmptyMessageDelayed(viewpager.getCurrentItem(), 2000);
   }

   /**
   * 添加小圆点
   */
   private void addLiner() {
       iv_list.clear();
       linear.removeAllViews();
       for(int i=0;i<imageurl.length;i++){
           ImageView imageview=new ImageView(MainActivity.this);
           if(i==0){
               imageview.setImageDrawable(getResources().getDrawable(R.drawable.format_and));
           }else{
               imageview.setImageDrawable(getResources().getDrawable(R.drawable.format_normal));
           }
           iv_list.add(imageview);

           LayoutParams params=new LayoutParams(20, 20);
           params.setMargins(5, 0, 5, 0);
           linear.addView(imageview, params);
       }
   }
}