模仿优酷Android客户端图片左右滑动(自动切换)效果
Java代码
- package com.tony.viewpager;
- import java.util.ArrayList;
- import java.util.List;
- import java.util.concurrent.Executors;
- import java.util.concurrent.ScheduledExecutorService;
- import java.util.concurrent.TimeUnit;
- import android.app.Activity;
- import android.os.Bundle;
- import android.os.Handler;
- import android.os.Parcelable;
- 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.widget.ImageView;
- import android.widget.ImageView.ScaleType;
- import android.widget.TextView;
- /**
- * 仿优酷Android客户端图片左右滑动
- *
- */
- public class MyViewPagerActivity extends Activity {
- private ViewPager viewPager; // android-support-v4中的滑动组件
- private List<ImageView> imageViews; // 滑动的图片集合
- private String[] titles; // 图片标题
- private int[] imageResId; // 图片ID
- private List<View> dots; // 图片标题正文的那些点
- private TextView tv_title;
- private int currentItem = 0; // 当前图片的索引号
- // An ExecutorService that can schedule commands to run after a given delay,
- // or to execute periodically.
- private ScheduledExecutorService scheduledExecutorService;
- // 切换当前显示的图片
- private Handler handler = new Handler() {
- public void handleMessage(android.os.Message msg) {
- viewPager.setCurrentItem(currentItem);// 切换当前显示的图片
- };
- };
- @Override
- public void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.main);
- imageResId = new int[] { R.drawable.a, R.drawable.b, R.drawable.c, R.drawable.d, R.drawable.e };
- titles = new String[imageResId.length];
- titles[0] = "巩俐不低俗,我就不能低俗";
- titles[1] = "扑树又回来啦!再唱经典老歌引万人大合唱";
- titles[2] = "揭秘北京电影如何升级";
- titles[3] = "乐视网TV版大派送";
- titles[4] = "热血屌丝的反杀";
- imageViews = new ArrayList<ImageView>();
- // 初始化图片资源
- for (int i = 0; i < imageResId.length; i++) {
- ImageView imageView = new ImageView(this);
- imageView.setImageResource(imageResId[i]);
- imageView.setScaleType(ScaleType.CENTER_CROP);
- imageViews.add(imageView);
- }
- dots = new ArrayList<View>();
- dots.add(findViewById(R.id.v_dot0));
- dots.add(findViewById(R.id.v_dot1));
- dots.add(findViewById(R.id.v_dot2));
- dots.add(findViewById(R.id.v_dot3));
- dots.add(findViewById(R.id.v_dot4));
- tv_title = (TextView) findViewById(R.id.tv_title);
- tv_title.setText(titles[0]);//
- viewPager = (ViewPager) findViewById(R.id.vp);
- viewPager.setAdapter(new MyAdapter());// 设置填充ViewPager页面的适配器
- // 设置一个监听器,当ViewPager中的页面改变时调用
- viewPager.setOnPageChangeListener(new MyPageChangeListener());
- }
- @Override
- protected void onStart() {
- scheduledExecutorService = Executors.newSingleThreadScheduledExecutor();
- // 当Activity显示出来后,每两秒钟切换一次图片显示
- scheduledExecutorService.scheduleAtFixedRate(new ScrollTask(), 1, 2, TimeUnit.SECONDS);
- super.onStart();
- }
- @Override
- protected void onStop() {
- // 当Activity不可见的时候停止切换
- scheduledExecutorService.shutdown();
- super.onStop();
- }
- /**
- * 换行切换任务
- *
- * @author Administrator
- *
- */
- private class ScrollTask implements Runnable {
- public void run() {
- synchronized (viewPager) {
- System.out.println("currentItem: " + currentItem);
- currentItem = (currentItem + 1) % imageViews.size();
- handler.obtainMessage().sendToTarget(); // 通过Handler切换图片
- }
- }
- }
- /**
- * 当ViewPager中页面的状态发生改变时调用
- *
- * @author Administrator
- *
- */
- private class MyPageChangeListener implements OnPageChangeListener {
- private int oldPosition = 0;
- /**
- * This method will be invoked when a new page becomes selected.
- * position: Position index of the new selected page.
- */
- public void onPageSelected(int position) {
- currentItem = position;
- tv_title.setText(titles[position]);
- dots.get(oldPosition).setBackgroundResource(R.drawable.dot_normal);
- dots.get(position).setBackgroundResource(R.drawable.dot_focused);
- oldPosition = position;
- }
- public void onPageScrollStateChanged(int arg0) {
- }
- public void onPageScrolled(int arg0, float arg1, int arg2) {
- }
- }
- /**
- * 填充ViewPager页面的适配器
- *
- * @author Administrator
- *
- */
- private class MyAdapter extends PagerAdapter {
- @Override
- public int getCount() {
- return imageResId.length;
- }
- @Override
- public Object instantiateItem(View arg0, int arg1) {
- ((ViewPager) arg0).addView(imageViews.get(arg1));
- return imageViews.get(arg1);
- }
- @Override
- public void destroyItem(View arg0, int arg1, Object arg2) {
- ((ViewPager) arg0).removeView((View) arg2);
- }
- @Override
- public boolean isViewFromObject(View arg0, Object arg1) {
- return arg0 == arg1;
- }
- @Override
- public void restoreState(Parcelable arg0, ClassLoader arg1) {
- }
- @Override
- public Parcelable saveState() {
- return null;
- }
- @Override
- public void startUpdate(View arg0) {
- }
- @Override
- public void finishUpdate(View arg0) {
- }
- }
- }