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
首先看一些layout下的xml
[html]
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]
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. 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. new ImageView[imgIdArray.length];
49. for(int i=0; i<tips.length; i++){
50. new ImageView(this);
51. 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. new LinearLayout.LayoutParams(new ViewGroup.LayoutParams(LayoutParams.WRAP_CONTENT,
60. LayoutParams.WRAP_CONTENT));
61. 5;
62. 5;
63. group.addView(imageView, layoutParams);
64. }
65.
66.
67. //将图片装载到数组中
68. new ImageView[imgIdArray.length];
69. for(int i=0; i<mImageViews.length; i++){
70. new ImageView(this);
71. mImageViews[i] = imageView;
72. imageView.setBackgroundResource(imgIdArray[i]);
73. }
74.
75. //设置Adapter
76. new MyAdapter());
77. //设置监听，主要是设置点点的背景
78. 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. 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. 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]
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]
1. @Override
2. public Object instantiateItem(View container, int position) {
3. try {
4. 0);
5. catch(Exception e){
6. //handler something
7. }
8. return mImageViews[position % mImageViews.length];
9. }
