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:



[java]
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<p>
</p><p><strong>然后是具体的布局文件及代码实现:</strong></p><p>main.xml:</p>
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#FFFFFF"
android:orientation="vertical" >

<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="40dip"
android:background="@drawable/title_bk" >

<ImageButton
android:id="@+id/btn_back"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@drawable/btn_back_selector"
android:src="@drawable/btn_back" />

<View
android:id="@+id/line0"
android:layout_width="1px"
android:layout_height="fill_parent"
android:layout_toRightOf="@id/btn_back"
android:background="#aa11264f" />

<View
android:layout_width="1px"
android:layout_height="fill_parent"
android:layout_toRightOf="@id/line0"
android:background="#009ad6" />

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:text="优酷客户端"
android:textColor="#FFFFFF"
android:textSize="20sp" />
</RelativeLayout>

<FrameLayout
android:layout_width="fill_parent"
android:layout_height="140dip" >

<android.support.v4.view.ViewPager
android:id="@+id/vp"
android:layout_width="fill_parent"
android:layout_height="fill_parent" />

<LinearLayout
android:layout_width="fill_parent"
android:layout_height="35dip"
android:layout_gravity="bottom"
android:background="#33000000"
android:gravity="center"
android:orientation="vertical" >

<TextView
android:id="@+id/tv_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="中国家庭院校园区域名字体现"
android:textColor="#ffffff" />

<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="3dip"
android:gravity="center" >

<View
android:id="@+id/v_dot0"
style="@style/dot_style"
android:background="@drawable/dot_focused" />

<View
android:id="@+id/v_dot1"
style="@style/dot_style" />

<View
android:id="@+id/v_dot2"
style="@style/dot_style" />

<View
android:id="@+id/v_dot3"
style="@style/dot_style" />

<View
android:id="@+id/v_dot4"
style="@style/dot_style" />
</LinearLayout>
</LinearLayout>
</FrameLayout>

</LinearLayout>

MyViewPagerActivity:

[java]
view plaincopy

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) {

}
}
}

Drawable目录下

btn_back_selector.xml:

[java]
view plaincopy

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

<item android:drawable="@drawable/btn_top_pressed" android:state_focused="true"></item>
<item android:drawable="@drawable/btn_top_pressed" android:state_pressed="true"></item>
<item android:drawable="@drawable/btn_top_pressed" android:state_selected="true"></item>
<item android:drawable="@drawable/title_bk"></item>

</selector>

btn_top_pressed.xml:

[java]
view plaincopy

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle" >

<gradient
android:angle="270"
android:endColor="#009ad6"
android:startColor="#11264f" />

</shape>

dot_focused.xml:

[java]
view plaincopy

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="oval" >

<solid android:color="#aaFFFFFF" />

<corners android:radius="5dip" />

</shape>

dot_normal.xml:

[java]
view plaincopy

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="oval" >

<solid android:color="#33000000" />

<corners android:radius="5dip" />

</shape>

title_bk.xml:

[java]
view plaincopy

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle" >

<gradient
android:angle="270"
android:endColor="#11264f"
android:startColor="#009ad6" />

</shape>

源码下载地址:

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

转载声明，原文出自：http://blog.csdn.net/t12x3456/article/details/8160128