android应用上常用的轮播图（viewpager实现）

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">

<android.support.v4.view.ViewPager
android:id="@+id/viewPager"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>

<RelativeLayout
android:layout_width="match_parent"
android:layout_gravity="bottom"
android:background="#e1e1e1"
android:layout_height="wrap_content">

<TextView
android:id="@+id/binnarTitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#ffffff" />
</RelativeLayout>
</FrameLayout>

BinnarAdapter

instantiateItem

@Override
public Object instantiateItem(ViewGroup container, int position) {
position %= imageViewList.size();
View viewGroup = imageViewList.get(position);
if (viewGroup.getParent() == null) {
container.addView(viewGroup);
}
return imageViewList.get(position);
}

@Override
public void destroyItem(ViewGroup container, int position, Object object) {
position %= imageViewList.size();
container.recomputeViewAttributes(imageViewList.get(position));
}

imageViewList是传进来的轮播图的网络地址
public void setBinnarUrls(List<ImageBean> imgUrls, ImageBinnarListner imageBinnarListner) {
this.imgUrls = imgUrls;
if (imageViewList == null) {
return;
}
ImageBean imageBean = imgUrls.get(0);
binnarTitle.setText(imageBean.getTitle());
imageViewList.clear();
for (ImageBean imgUrl : imgUrls) {
ImageView imageView = new ImageView(context);
if (imageBinnarListner != null) {
imageBinnarListner.LoadImage(imageView, imgUrl.getImgUrl());
}
imageViewList.add(imageView);
}
binnarAdapter.notifyDataSetChanged();
}

[code]

这下手动滑动就没问题了。加载图片的方式用了一个回调在外面进行加载。

如果要想加viewpager自动滑动再用一个定时任务执行handler来完成

private void startAutoScroll() {
executor = Executors.newSingleThreadScheduledExecutor();
executor.scheduleAtFixedRate(new Runnable() {
@Override
public void run() {
//                synchronized (this) {
if (isPress) {//按下状态停止自动滚动
return;
}
curIndex = viewPager.getCurrentItem();
curIndex += 1;
curIndex = curIndex >= imageViewList.size() ? 0 : curIndex;
binnarHandler.obtainMessage().sendToTarget();
}
//            }
}, INITIAL_DELAY, PERIOD, TimeUnit.SECONDS);
}


用到这步感觉viewpager自动切换 的时候动画根本 看不到。然后就有很多用放弃viewpager用ViewFlipper，暂时还没有去研究这个动画切换

调用些自定义binnar也就一个方法

imageBinnar.setBinnarUrls(urlList, new ImageBinnar.ImageBinnarListner() {
@Override
public void LoadImage(ImageView imageView, String imageUrl) {
Picasso.with(MainActivity.this)
.load(imageUrl)
.error(R.mipmap.ic_launcher)
.into(imageView);
}
});