实现无限循环
在getCount()方法中，返回一个很大的值，Integer.MAX_VALUE
在instantiateItem()方法中，获取当前View的索引时，进行取于操作，传递进来的int position是个非常大的数，对他进行求余数
在destroyItem()方法中，同样
在onPageSelected()监听方法中，对传递进来的索引进行取于
反向的无限循环
调用ViewPager对象的setCurrentItem()方法，设置第一次进来时候的当前页，参数：int数字，我们把它定位到Integer.MAX_VALUE的中间，并且保证第一条是当前位置，Integer.MAX_VALUE/2-((Integer.MAX_VALUE/2)%banners.size())
目前有个左划空白页的问题没解决
package com.tsh.myviewpager; import java.util.ArrayList; import java.util.List; import android.app.Activity; import android.os.Bundle; import android.support.v4.view.PagerAdapter; import android.support.v4.view.ViewPager; import android.support.v4.view.ViewPager.OnPageChangeListener; import android.view.View; import android.view.ViewGroup; import android.widget.ImageView; import android.widget.LinearLayout; import android.widget.TextView; public class MainActivity extends Activity { private ViewPager vp_banner; private LinearLayout ll_points; private TextView tv_title; private List<View> banners; private String[] titles=new String[]{ "新闻标题1", "新闻标题2", "新闻标题3" }; private List<ImageView> points=new ArrayList<ImageView>(); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // 初始化 vp_banner = (ViewPager) findViewById(R.id.vp_banner); ll_points = (LinearLayout) findViewById(R.id.ll_points); tv_title = (TextView) findViewById(R.id.tv_title); // banner部分 banners = new ArrayList<>(); ImageView img1 = new ImageView(this); img1.setImageResource(R.drawable.a); banners.add(img1); ImageView img2 = new ImageView(this); img2.setImageResource(R.drawable.b); banners.add(img2); ImageView img3 = new ImageView(this); img3.setImageResource(R.drawable.c); banners.add(img3); //小图标 ll_points=(LinearLayout) findViewById(R.id.ll_points); for(int i=0;i<banners.size();i++){ ImageView image=new ImageView(this); image.setImageResource(R.drawable.point_selector); LinearLayout.LayoutParams params=new LinearLayout.LayoutParams(5, 5); params.rightMargin=4; image.setLayoutParams(params); if(i==0){ image.setEnabled(true); }else{ image.setEnabled(false); } points.add(image); ll_points.addView(image); } // 设置适配器 vp_banner.setAdapter(new MyPagerAdapter()); vp_banner.setCurrentItem(Integer.MAX_VALUE/2-((Integer.MAX_VALUE/2)%banners.size())); vp_banner.setOnPageChangeListener(new OnPageChangeListener() { @Override public void onPageSelected(int arg0) { tv_title.setText(titles[arg0%banners.size()]); //小图标处理 for(ImageView point:points){ point.setEnabled(false); } points.get(arg0%banners.size()).setEnabled(true); } @Override public void onPageScrolled(int arg0, float arg1, int arg2) { // TODO Auto-generated method stub } @Override public void onPageScrollStateChanged(int arg0) { // TODO Auto-generated method stub } }); } private class MyPagerAdapter extends PagerAdapter { @Override public void destroyItem(ViewGroup container, int position, Object object) { System.out.println("销毁："+position); container.removeView((View)object); object=null; } @Override public Object instantiateItem(ViewGroup container, int position) { System.out.println("初始化："+position); position=position%banners.size(); //解决右划出错 if(banners.get(position).getParent()!=null){ //container.removeView(banners.get(position)); }else{ container.addView(banners.get(position)); } return banners.get(position); } @Override public int getCount() { return Integer.MAX_VALUE; } @Override public boolean isViewFromObject(View arg0, Object arg1) { return arg0 == arg1; } } }
原创文章，作者：奋斗，如若转载，请注明出处：https://blog.ytso.com/5403.html