Viewpager自动轮播，可修改滑动速度

Viewpager自动轮播，间隔时间5秒：

如果五秒内用户没有手动滑动viewpager，则自动跳转到下一页

/**
* 配置viewPager
*/
private ExecutorService mExecutorService = Executors.newCachedThreadPool();//创建一个可缓存线程池
private int count = 0;//每次页面跳转时计数+1
private final ThreadLocal<Integer> selectcount = new ThreadLocal<Integer>() {
@Override
protected Integer initialValue() {
return 0;
}
};

public void setViewPager() {
MyVPagerAdapter adapter = new MyVPagerAdapter(getActivity());

mViewPager.setAdapter(adapter);
//设置滑动速度
try {
Field mScroller = ViewPager.class.getDeclaredField("mScroller");
mScroller.setAccessible(true);
ChangeSpeedScroller scroller = new ChangeSpeedScroller(mViewPager.getContext(), new AccelerateInterpolator());
scroller.setDuration(200);
mScroller.set(mViewPager, scroller);
} catch (NoSuchFieldException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
}

//viewPager间隔5秒自动滑动
final Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
//跳转到下一页
mViewPager.setCurrentItem(mViewPager.getCurrentItem() + 1);
}
};
mViewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(final int position, final float positionOffset, int positionOffsetPixels) {
}

@Override
public void onPageSelected(int position) {

count++;
//开启新线程
mExecutorService.execute(new Runnable() {
@Override
public void run() {
//启动线程时将当前的count赋值给selectcount
selectcount.set(count);
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
e.printStackTrace();
}
//线程沉睡5秒之后如果selectcount==count，即count值未发生改变,即viewpager未发生跳转
if (selectcount.get() == count) {
//线程沉睡期间页面未发生跳转则发送消息，否则不发送此条消息
mHandler.sendEmptyMessage(0);
}
}
});
}

@Override
public void onPageScrollStateChanged(int state) {
}
});

//初始设置为第6000个item，使viewpager开始时就支持用户手动向前滑动，其实只要设置个不是太小的数就行，没人会无聊到一直往前翻页
mViewPager.setCurrentItem(6000);
}

修改Viewpager滑动速度的工具类:

import android.content.Context;
import android.view.animation.Interpolator;
import android.widget.Scroller;

/**
* Created by DR66 on 2016/6/15.
* 继承scroller类，可实现修改滑动速度
* 外部调用setDuration()即可修改滑动速度
*/
public class ChangeSpeedScroller extends Scroller {
private int mDuration=250;

public void setDuration(int duration) {
mDuration = duration;
}

public ChangeSpeedScroller(Context context){
super(context);
}
public ChangeSpeedScroller(Context context, Interpolator interpolator){
super(context,interpolator);
}
public ChangeSpeedScroller(Context context, Interpolator interpolator,boolean flywheel){
super(context,interpolator,flywheel);
}

@Override
public void startScroll(int startX, int startY, int dx, int dy, int duration) {
super.startScroll(startX, startY, dx, dy, mDuration);
}

@Override
public void startScroll(int startX, int startY, int dx, int dy) {
super.startScroll(startX, startY, dx, dy);
}
}

viewpager适配器，轮播页面是6页，这里的特别之处就是设置getCount（）为一个很大的数，保证在手机关机前viewpager仍然没有跳转到最后一页

/**
* by Dovar66 on 2016/6/6.
* My life my tude!
*/
public class MyVPagerAdapter extends PagerAdapter {
private int[] img = {R.drawable.viewpager01, R.drawable.viewpager02, R.drawable.viewpager03, R.drawable.viewpager04, R.drawable.viewpager05, R.drawable.viewpager06};
private Context mContext;

public MyVPagerAdapter(Context context) {
mContext = context;
}

@Override
public int getCount() {
return 100000;
}

@Override
public boolean isViewFromObject(View view, Object object) {
return view==object;
}

@Override
public Object instantiateItem(ViewGroup container, int position) {

ImageView iv = new ImageView(mContext);
iv.setImageResource(img[position%6]);
iv.setScaleType(ImageView.ScaleType.FIT_XY);
container.addView(iv);
return iv;
}

@Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((View)object);
}
}

我重新整理封装成了AutoViewPager，完整Demo查看请移步