Android实现轮播图无限循环效果
本文实例为大家分享了Android轮播图无限循环的具体代码，供大家参考，具体内容如下
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intposition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
packagecom.tsh.myviewpager;
importjava.util.ArrayList;
importjava.util.List;
importandroid.app.Activity;
importandroid.os.Bundle;
importandroid.support.v4.view.PagerAdapter;
importandroid.support.v4.view.ViewPager;
importandroid.support.v4.view.ViewPager.OnPageChangeListener;
importandroid.view.View;
importandroid.view.ViewGroup;
importandroid.widget.ImageView;
importandroid.widget.LinearLayout;
importandroid.widget.TextView;
publicclassMainActivityextendsActivity{
privateViewPagervp_banner;
privateLinearLayoutll_points;
privateTextViewtv_title;
privateList<View>banners;
privateString[]titles=newString[]{
"新闻标题1",
"新闻标题2",
"新闻标题3"
};
privateList<ImageView>points=newArrayList<ImageView>();
@Override
protectedvoidonCreate(BundlesavedInstanceState){
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=newArrayList<>();
ImageViewimg1=newImageView(this);
img1.setImageResource(R.drawable.a);
banners.add(img1);
ImageViewimg2=newImageView(this);
img2.setImageResource(R.drawable.b);
banners.add(img2);
ImageViewimg3=newImageView(this);
img3.setImageResource(R.drawable.c);
banners.add(img3);
//小图标
ll_points=(LinearLayout)findViewById(R.id.ll_points);
for(inti=0;i<banners.size();i++){
ImageViewimage=newImageView(this);
image.setImageResource(R.drawable.point_selector);
LinearLayout.LayoutParamsparams=newLinearLayout.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(newMyPagerAdapter());
vp_banner.setCurrentItem(Integer.MAX_VALUE/2-((Integer.MAX_VALUE/2)%banners.size()));
vp_banner.setOnPageChangeListener(newOnPageChangeListener(){
@Override
publicvoidonPageSelected(intarg0){
tv_title.setText(titles[arg0%banners.size()]);
//小图标处理
for(ImageViewpoint:points){
point.setEnabled(false);
}
points.get(arg0%banners.size()).setEnabled(true);
}
@Override
publicvoidonPageScrolled(intarg0,floatarg1,intarg2){
//TODOAuto-generatedmethodstub
}
@Override
publicvoidonPageScrollStateChanged(intarg0){
//TODOAuto-generatedmethodstub
}
});
}
privateclassMyPagerAdapterextendsPagerAdapter{
@Override
publicvoiddestroyItem(ViewGroupcontainer,intposition,Objectobject){
System.out.println("销毁："+position);
container.removeView((View)object);
object=null;
}
@Override
publicObjectinstantiateItem(ViewGroupcontainer,intposition){
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));
}
returnbanners.get(position);
}
@Override
publicintgetCount(){
returnInteger.MAX_VALUE;
}
@Override
publicbooleanisViewFromObject(Viewarg0,Objectarg1){
returnarg0==arg1;
}
}
}
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持毛票票。