目录
0、介绍
用Handler实现自动轮播
系列文章:
Android使用ViewPager实现图片轮播系列之一:简单实现
Android使用ViewPager实现图片轮播系列之三:手动滑动 + 左右箭头
Android使用ViewPager实现图片轮播系列之四:手动滑动 + 左右箭头 + 删除数据
1、布局文件
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.gs.common3.aView.viewpager.VPTest2Activity">
<android.support.v4.view.ViewPager
android:id="@+id/viewPager"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</android.support.constraint.ConstraintLayout>
2、VPTest2Activity.java
/**
* Android使用ViewPager实现图片轮播系列之二:自动轮播
*/
public class VPTest2Activity extends AppCompatActivity {
@BindView(R.id.viewPager)
ViewPager viewPager;
private int[] imagePaths = {
R.mipmap.scenery1, R.mipmap.scenery2, R.mipmap.scenery3, R.mipmap.scenery4,
R.mipmap.scenery5
};
ArrayList<ImageView> imageViewList;
private MyPagerAdapter myPagerAdapter;
private int currentItem = 0;
//定时轮播
@SuppressLint("HandlerLeak")
private Handler timeHandler = new Handler() {
public void handleMessage(Message msg) {
if (msg.what == 1) {
/*** 此处如果设置 currentItem % imageViewList.size() 能够让其不间断轮播
* 如果设置 currentItem 到最后一张图片就停止了 */
if (imageViewList.size() != 0) {
int num = currentItem % imageViewList.size();
LogUtils.e(num + "");
viewPager.setCurrentItem(num);
}
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_vptest2);
ButterKnife.bind(this);
initData();
autoPlay();
}
private void initData() {
imageViewList = new ArrayList<>();
viewPager.setCurrentItem(0);
setDataToViewPager();
}
/**
* 把数据设置到 ViewPager 上
*/
private void setDataToViewPager() {
// 将图片放到集合中
imageViewList = new ArrayList<>();
for (int imagePath : imagePaths) {
ImageView imageView = new ImageView(this);
imageView.setImageResource(imagePath);
// Glide.with(this).load(imagePath).into(imageView);
imageView.setScaleType(ImageView.ScaleType.FIT_XY);
imageViewList.add(imageView);
}
// 进行适配
myPagerAdapter = new MyPagerAdapter();
viewPager.setAdapter(myPagerAdapter);
}
/**
* 设置自动播放
*/
private void autoPlay() {
new Thread() {
@Override
public void run() {
super.run();
while (true) {
//轮播间隔时间
SystemClock.sleep(2 * 1000);
currentItem++;
timeHandler.sendEmptyMessage(1);
}
}
}.start();
}
/**
* 自定义适配器
*/
private class MyPagerAdapter extends PagerAdapter {
@Override
public int getCount() {
return imageViewList.size();
}
@Override
public Object instantiateItem(ViewGroup container, final int position) {
ImageView imageView = imageViewList.get(position);
ViewParent viewParent = imageView.getParent();
if (viewParent != null) {
ViewGroup viewGroup = (ViewGroup) viewParent;
viewGroup.removeView(imageView);
}
container.addView(imageView);
return imageView;
}
@Override
public void destroyItem(View view, int num, Object object) {
}
@Override
public boolean isViewFromObject(View view, Object object) {
return view == object;
}
}
}