高仿优酷Android客户端图片左右滑动（自动切换）

本例是用ViewPager去做的实现，支持自动滑动和手动滑动，不仅优酷网，实际上有很多商城和门户网站都有类似的实现:

具体思路：

1. 工程中需要添加android-support-v4.jar,才能使用ViewPager控件.

2. 图片的自动切换: 可使用Timer或者ScheduledExecutorService,这个有多重方式可以实现.

同时要切换底部的dots（园点）

3.Handler+Message机制更新UI,这个相信大家都很熟练，不再描述

4. 实现的一些细节:注意本例中的优化：图片的自动切换启动了其他的线程，要在Activity在可见到不可见的状态,也就是在onStop()方法中将线程停止，在onStart()方法中开启线程。否则，Timer没有停止，或者反复开启，会引起较大的内存消耗，时间一长就程序就会崩掉。 还有，就是在跳转到其他Activity的过程中会出现画面的卡顿

下面看一下效果图和具体代码:

工程结构如下图所示：

main.xml:

然后是具体的布局文件及代码实现:

main.xml:

MyViewPagerActivity:

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 imageViews; // 滑动的图片集合

	private String[] titles; // 图片标题
	private int[] imageResId; // 图片ID
	private List 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();

		// 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();
		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) {

		}
	}
}

Drawable目录下
btn_back_selector.xml:

btn_top_pressed.xml:

dot_focused.xml:

dot_normal.xml:

title_bk.xml:

源码下载地址:

http://download.csdn.net/detail/t12x3456/4751688