Android教程：使用ViewPager實現左右循環滑動

前面一篇文章實現了使用ViewPager實現高仿launcher拖動效果 ，後來很多朋友問能不能實現左右循環滑動效果和引導頁面。今天實現了左右滑動，至於在最後一頁滑動跳轉，這個也做了但是效果不是太好，也希望有實現的朋友能夠分享下。在最後一頁添加一張圖片單擊跳轉，這個認為很簡單大家自己添加個圖片，點擊後跳轉就OK。

這篇是在實現了使用ViewPager實現高仿launcher拖動效果的基礎上做了一些小的修改，可以參照前面的。廢話不多說了，直接上代碼吧！

首先看一些layout下的xml

1. <?xml version="1.0" encoding="utf-8"?>
2. <FrameLayout xmlns:Android="http://schemas.android.com/apk/res/android"
3. android:layout_width="fill_parent"
4. android:layout_height="fill_parent"
5. android:orientation="vertical" >
7. <android.support.v4.view.ViewPager
8. android:id="@+id/viewPager"
9. android:layout_width="fill_parent"
10. android:layout_height="wrap_content" />
12. <RelativeLayout
13. android:layout_width="fill_parent"
14. android:layout_height="wrap_content"
15. android:orientation="vertical" >
17. <LinearLayout
18. android:id="@+id/viewGroup"
19. android:layout_width="fill_parent"
20. android:layout_height="wrap_content"
21. android:layout_alignParentBottom="true"
22. android:layout_marginBottom="30dp"
23. android:gravity="center_horizontal"
24. android:orientation="horizontal" >
25. </LinearLayout>
26. </RelativeLayout>
28. </FrameLayout>

和前面一頁使用viewpager。使用ViewPager首先需要引入android-support-v4.jar這個jar包。自己不要忘記加。

下面是核心代碼：

1. package cn.com.karl.viewpager;
3. import java.util.ArrayList;
6. import android.app.Activity;
7. import android.content.Intent;
8. import android.os.Bundle;
9. import android.os.Parcelable;
10. import android.support.v4.view.PagerAdapter;
11. import android.support.v4.view.ViewPager;
12. import android.support.v4.view.ViewPager.OnPageChangeListener;
13. import android.util.Log;
14. import android.view.LayoutInflater;
15. import android.view.View;
16. import android.view.ViewGroup;
17. import android.view.ViewGroup.LayoutParams;
18. import android.view.Window;
19. import android.widget.ImageView;
21. public class MainActivity extends Activity {
22. ViewPager viewPager;
23. ArrayList<View> list;
24. ViewGroup main, group;
25. ImageView imageView;
26. ImageView[] imageViews;
27. private static int c_id = 0;
28. @Override
29. public void onCreate(Bundle savedInstanceState) {
30. super.onCreate(savedInstanceState);
31. this.requestWindowFeature(Window.FEATURE_NO_TITLE);
32. LayoutInflater inflater = getLayoutInflater();
33. list = new ArrayList<View>();
34. list.add(inflater.inflate(R.layout.item1, null));
35. list.add(inflater.inflate(R.layout.item2, null));
36. list.add(inflater.inflate(R.layout.item3, null));
37. list.add(inflater.inflate(R.layout.item4, null));
38. list.add(inflater.inflate(R.layout.item5, null));
40. imageViews = new ImageView[list.size()];
41. ViewGroup main = (ViewGroup) inflater.inflate(R.layout.main, null);
43. ViewGroup group = (ViewGroup) main.findViewById(R.id.viewGroup);
45. viewPager = (ViewPager) main.findViewById(R.id.viewPager);
47. for (int i = 0; i < list.size(); i++) {
48. imageView = new ImageView(MainActivity.this);
49. imageView.setLayoutParams(new LayoutParams(12,12));
50. //imageView.setPadding(10, 0, 10, 0);
51. imageViews[i] = imageView;
52. if (i == 0) {
54. imageViews[i].setBackgroundResource(R.drawable.guide_dot_white);
55. } else {
56. imageViews[i].setBackgroundResource(R.drawable.guide_dot_black);
57. }
58. group.addView(imageView);
59. }
61. setContentView(main);
63. viewPager.setAdapter(new MyAdapter());
64. viewPager.setOnPageChangeListener(new MyListener());
65. viewPager.setCurrentItem(300);
67. }
69. class MyAdapter extends PagerAdapter {
71. @Override
72. public int getCount() {
73. return Integer.MAX_VALUE;
74. }
76. @Override
77. public boolean isViewFromObject(View arg0, Object arg1) {
78. return arg0 == arg1;
79. }
81. @Override
82. public int getItemPosition(Object object) {
83. // TODO Auto-generated method stub
84. return super.getItemPosition(object);
85. }
87. @Override
88. public void destroyItem(View arg0, int arg1, Object arg2) {
89. // TODO Auto-generated method stub
90. //((ViewPager) arg0).removeView(list.get(arg1));
91. }
93. @Override
94. public Object instantiateItem(View arg0, int arg1) {
95. // TODO Auto-generated method stub
96. try{
97. ((ViewPager) arg0).addView(list.get(arg1%list.size()),0);
98. }catch (Exception e) {
99. // TODO: handle exception
100. }
101. return list.get(arg1%list.size());
102. }
104. @Override
105. public void restoreState(Parcelable arg0, ClassLoader arg1) {
106. // TODO Auto-generated method stub
108. }
110. @Override
111. public Parcelable saveState() {
112. // TODO Auto-generated method stub
113. return null;
114. }
116. @Override
117. public void startUpdate(View arg0) {
118. // TODO Auto-generated method stub
120. }
122. @Override
123. public void finishUpdate(View arg0) {
124. // TODO Auto-generated method stub
126. }
127. }
129. class MyListener implements OnPageChangeListener {
131. //當滑動狀態改變時調用
132. @Override
133. public void onPageScrollStateChanged(int arg0) {
134. // TODO Auto-generated method stub
135. //arg0=arg0%list.size();
137. }
139. //當當前頁面被滑動時調用
140. @Override
141. public void onPageScrolled(int arg0, float arg1, int arg2) {
142. // TODO Auto-generated method stub
144. }
146. //當新的頁面被選中時調用
147. @Override
148. public void onPageSelected(int arg0) {
149. if(arg0>2){
150. arg0=arg0%list.size();
151. }
152. c_id = arg0;
153. for (int i = 0; i < imageViews.length; i++) {
154. imageViews[arg0]
155. .setBackgroundResource(R.drawable.guide_dot_white);
156. if (arg0 != i) {
157. imageViews[i]
158. .setBackgroundResource(R.drawable.guide_dot_black);
159. }
160. }
162. Log.e("-------------", "當前是第"+c_id+"頁");
163. }
165. }
166. }

代碼跟上一篇差不多，大家自己研究吧！下面看下效果：

忘記了，這種效果不太好用圖片演示，大家自己演示吧！滑動到最後一張，再滑動就是進入了第一頁。下面看下我logcat下的打印：

這裡默認是從第0頁開始的。

更多Android相關信息見Android 專題頁面 http://www.linuxidc.com/topicnews.aspx?tid=11