ViewPager这个小demo实现的是可以左右循环滑动图片，下面带索引，滑到最后一页在往右滑动就要第一页，第一页往左滑动就到最后一页，先上效果图，用美女图片是我一贯的作风，呵呵

1.    首先看一些layout下的xml

[html] view plaincopy

 

1. <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"  
2.     android:layout_width="fill_parent"  
3.     android:layout_height="fill_parent"  
4.     android:orientation="vertical" >  
5.       
6.    <android.support.v4.view.ViewPager    
7.         android:id="@+id/viewPager"    
8.         android:layout_width="fill_parent"    
9.         android:layout_height="wrap_content" />   
10.           
11.     <RelativeLayout    
12.         android:layout_width="fill_parent"    
13.         android:layout_height="wrap_content"   
14.         android:orientation="vertical" >    
15.     
16.         <LinearLayout    
17.             android:id="@+id/viewGroup"    
18.             android:layout_width="fill_parent"    
19.             android:layout_height="wrap_content"    
20.             android:layout_alignParentBottom="true"   
21.             android:layout_marginBottom="30dp"    
22.             android:gravity="center_horizontal"    
23.             android:orientation="horizontal" >    
24.         </LinearLayout>    
25.     </RelativeLayout>    
26.   
27. </FrameLayout>  

使用ViewPager首先需要引入android-support-v4.jar这个jar包。自己不要忘记加

[java] view plaincopy

 

1. package com.example.viewpagerdemo;  
2.   
3. import android.app.Activity;  
4. import android.os.Bundle;  
5. import android.support.v4.view.PagerAdapter;  
6. import android.support.v4.view.ViewPager;  
7. import android.support.v4.view.ViewPager.OnPageChangeListener;  
8. import android.view.View;  
9. import android.view.ViewGroup;  
10. import android.view.ViewGroup.LayoutParams;  
11. import android.widget.ImageView;  
12. import android.widget.LinearLayout;  
13.   
14. public class TwoActivity extends Activity implements OnPageChangeListener{  
15.     /** 
16.      * ViewPager 
17.      */  
18.     private ViewPager viewPager;  
19.       
20.     /** 
21.      * 装点点的ImageView数组 
22.      */  
23.     private ImageView[] tips;  
24.       
25.     /** 
26.      * 装ImageView数组 
27.      */  
28.     private ImageView[] mImageViews;  
29.       
30.     /** 
31.      * 图片资源id 
32.      */  
33.     private int[] imgIdArray ;  
34.   
35.     @Override  
36.     protected void onCreate(Bundle savedInstanceState) {  
37.         super.onCreate(savedInstanceState);  
38.         setContentView(R.layout.activity_main);  
39.         ViewGroup group = (ViewGroup)findViewById(R.id.viewGroup);  
40.         viewPager = (ViewPager) findViewById(R.id.viewPager);  
41.           
42.         //载入图片资源ID  
43.         imgIdArray = new int[]{R.drawable.item01, R.drawable.item02, R.drawable.item03, R.drawable.item04,  
44.                 R.drawable.item05,R.drawable.item06, R.drawable.item07, R.drawable.item08};  
45.           
46.           
47.         //将点点加入到ViewGroup中  
48.         tips = new ImageView[imgIdArray.length];  
49.         for(int i=0; i<tips.length; i++){  
50.             ImageView imageView = new ImageView(this);  
51.             imageView.setLayoutParams(new LayoutParams(10,10));  
52.             tips[i] = imageView;  
53.             if(i == 0){  
54.                 tips[i].setBackgroundResource(R.drawable.page_indicator_focused);  
55.             }else{  
56.                 tips[i].setBackgroundResource(R.drawable.page_indicator_unfocused);  
57.             }  
58.               
59.             LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(new ViewGroup.LayoutParams(LayoutParams.WRAP_CONTENT,    
60.                     LayoutParams.WRAP_CONTENT));  
61.             layoutParams.leftMargin = 5;  
62.             layoutParams.rightMargin = 5;  
63.             group.addView(imageView, layoutParams);  
64.         }  
65.           
66.           
67.         //将图片装载到数组中  
68.         mImageViews = new ImageView[imgIdArray.length];  
69.         for(int i=0; i<mImageViews.length; i++){  
70.             ImageView imageView = new ImageView(this);  
71.             mImageViews[i] = imageView;  
72.             imageView.setBackgroundResource(imgIdArray[i]);  
73.         }  
74.           
75.         //设置Adapter  
76.         viewPager.setAdapter(new MyAdapter());  
77.         //设置监听，主要是设置点点的背景  
78.         viewPager.setOnPageChangeListener(this);  
79.         //设置ViewPager的默认项, 设置为长度的100倍，这样子开始就能往左滑动  
80.         viewPager.setCurrentItem((mImageViews.length) * 100);  
81.           
82.     }  
83.       
84.     /** 
85.      *  
86.      * @author xiaanming 
87.      * 
88.      */  
89.     public class MyAdapter extends PagerAdapter{  
90.   
91.         @Override  
92.         public int getCount() {  
93.             return Integer.MAX_VALUE;  
94.         }  
95.   
96.         @Override  
97.         public boolean isViewFromObject(View arg0, Object arg1) {  
98.             return arg0 == arg1;  
99.         }  
100.   
101.         @Override  
102.         public void destroyItem(View container, int position, Object object) {  
103.             ((ViewPager)container).removeView(mImageViews[position % mImageViews.length]);  
104.               
105.         }  
106.   
107.         /** 
108.          * 载入图片进去，用当前的position 除以 图片数组长度取余数是关键 
109.          */  
110.         @Override  
111.         public Object instantiateItem(View container, int position) {  
112.             ((ViewPager)container).addView(mImageViews[position % mImageViews.length], 0);  
113.             return mImageViews[position % mImageViews.length];  
114.         }  
115.           
116.           
117.           
118.     }  
119.   
120.     @Override  
121.     public void onPageScrollStateChanged(int arg0) {  
122.           
123.     }  
124.   
125.     @Override  
126.     public void onPageScrolled(int arg0, float arg1, int arg2) {  
127.           
128.     }  
129.   
130.     @Override  
131.     public void onPageSelected(int arg0) {  
132.         setImageBackground(arg0 % mImageViews.length);  
133.     }  
134.       
135.     /** 
136.      * 设置选中的tip的背景 
137.      * @param selectItems 
138.      */  
139.     private void setImageBackground(int selectItems){  
140.         for(int i=0; i<tips.length; i++){  
141.             if(i == selectItems){  
142.                 tips[i].setBackgroundResource(R.drawable.page_indicator_focused);  
143.             }else{  
144.                 tips[i].setBackgroundResource(R.drawable.page_indicator_unfocused);  
145.             }  
146.         }  
147.     }  
148.   
149. }  

代码下载

上面的代码中，当只有3张图片或者2张图片的时候，滑动存在BUG问题的修改如下

• destroyItem(View container, int position, Object object)方法中不removeView

[java] view plaincopy

 

1.     @Override  
2.         public void destroyItem(View container, int position, Object object) {  
3. //          ((ViewPager)container).removeView(mImageViews[position % mImageViews.length]);  
4.         }  

• instantiateItem(View container, int position)增加异常扑捉

[java] view plaincopy

 

1. @Override  
2.     public Object instantiateItem(View container, int position) {  
3.         try {    
4.             ((ViewPager)container).addView(mImageViews[position % mImageViews.length], 0);  
5.         }catch(Exception e){  
6.             //handler something  
7.         }  
8.         return mImageViews[position % mImageViews.length];  
9.     }  

Android 使用ViewPager实现左右循环滑动图片