最近做项目要用到IPHONE 左右滑动特效,想想只能用viewpager才能实现,先看效果,就是左右滑屏的效果
具体实现详解
android compatibility package, revision 3在7月份发布后,其中有个ViewPager引起了我的注意
官方的描述:
请参考:http://developer.android.com/sdk/compatibility-library.html#Notes
ViewPager的下载与安装
首先通过SDK Manager更新最新版android compatibility package, revision 3
更新后,在eclipse中工程上点击右键,选择android tools -> add compatibility library即可完成安装
实际上就是一个jar包,手工导到工程中也可
jar包所在位置是\android-sdk\extras\android\compatibility\v4\android-support-v4.jar
至此准备环境已经ok
下边还是通过代码进行说话吧
准备布局文件
viewpager_layout.xml
1 <?xml version="1.0" encoding="utf-8"?>
2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
3android:layout_width="fill_parent"
4android:layout_height="fill_parent" android:orientation="vertical">
5 <!-- 此处需要给出全路径 -->
6 <android.support.v4.view.ViewPager
7android:id="@+id/viewpagerLayout" android:layout_height="fill_parent"android:layout_width="fill_parent"/>
8 </LinearLayout>
layout1.xml
1 <?xml version="1.0" encoding="utf-8"?>
2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
3android:layout_width="fill_parent"
4android:layout_height="fill_parent" android:orientation="vertical">
5<TextView android:textAppearance="?android:attr/textAppearanceLarge"android:layout_height="wrap_content" android:id="@+id/textView1"android:layout_width="fill_parent" android:text="第一页"></TextView>
6<EditText android:layout_width="match_parent" android:layout_height="wrap_content"android:id="@+id/editText1">
7<requestFocus></requestFocus>
8</EditText>
9 </LinearLayout>
layout2.xml
1 <?xml version="1.0" encoding="utf-8"?>
2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
3android:layout_width="fill_parent"
4android:layout_height="fill_parent" android:orientation="vertical">
5<TextView android:textAppearance="?android:attr/textAppearanceLarge"android:layout_height="wrap_content" android:id="@+id/textView1"android:layout_width="fill_parent" android:text="第二页"></TextView>
6<EditText android:layout_width="match_parent" android:layout_height="wrap_content"android:id="@+id/editText1">
7<requestFocus></requestFocus>
8</EditText>
9 </LinearLayout>
layout3.xml
1 <?xml version="1.0" encoding="utf-8"?>
2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
3android:layout_width="fill_parent"
4android:layout_height="fill_parent" android:orientation="vertical">
5<TextView android:textAppearance="?android:attr/textAppearanceLarge"android:layout_height="wrap_content" android:id="@+id/textView1"android:layout_width="fill_parent" android:text="第三页"></TextView>
6<EditText android:layout_width="match_parent" android:layout_height="wrap_content"android:id="@+id/editText1">
7<requestFocus></requestFocus>
8</EditText>
9 </LinearLayout>
主程序
001 package a.b;
002
003 import java.util.ArrayList;
004 import java.util.List;
005
006 import android.app.Activity;
007 import android.os.Bundle;
008 import android.os.Parcelable;
009 import android.support.v4.view.PagerAdapter;
010 import android.support.v4.view.ViewPager;
011 import android.support.v4.view.ViewPager.OnPageChangeListener;
012 import android.util.Log;
013 import android.view.LayoutInflater;
014 import android.view.View;
015 import android.widget.EditText;
016
017 public class TestViewPager extends Activity {
018private ViewPager myViewPager;
019
020private MyPagerAdapter myAdapter;
021
022private LayoutInflater mInflater;
023private List<View> mListViews;
024private View layout1 = null;
025private View layout2 = null;
026private View layout3 = null;
027
028@Override
029protected void onCreate(Bundle savedInstanceState) {
030super.onCreate(savedInstanceState);
031setContentView(R.layout.viewpager_layout);
032myAdapter = new MyPagerAdapter();
033myViewPager = (ViewPager) findViewById(R.id.viewpagerLayout);
034myViewPager.setAdapter(myAdapter);
035
036mListViews = new ArrayList<View>();
037mInflater = getLayoutInflater();
038layout1 = mInflater.inflate(R.layout.layout1, null);
039layout2 = mInflater.inflate(R.layout.layout2, null);
040layout3 = mInflater.inflate(R.layout.layout3, null);
041
042mListViews.add(layout1);
043mListViews.add(layout2);
044mListViews.add(layout3);
045
046//初始化当前显示的view
047myViewPager.setCurrentItem(1);
048
049//初始化第二个view的信息
050EditText v2EditText = (EditText)layout2.findViewById(R.id.editText1);
051v2EditText.setText("动态设置第二个view的值");
052
053myViewPager.setOnPageChangeListener(new OnPageChangeListener() {
054
055@Override
056public void onPageSelected(int arg0) {
057Log.d("k", "onPageSelected - " + arg0);
058//activity从1到2滑动,2被加载后掉用此方法
059View v = mListViews.get(arg0);
060EditText editText = (EditText)v.findViewById(R.id.editText1);
061editText.setText("动态设置#"+arg0+"edittext控件的值");
062}
063
064@Override
065public void onPageScrolled(int arg0, float arg1, int arg2) {
066Log.d("k", "onPageScrolled - " + arg0);
067//从1到2滑动,在1滑动前调用
068}
069
070@Override
071public void onPageScrollStateChanged(int arg0) {
072Log.d("k", "onPageScrollStateChanged - " + arg0);
073//状态有三个0空闲,1是增在滑行中,2目标加载完毕
074/**
075* Indicates that the pager is in an idle, settled state. The current page
076* is fully in view and no animation is in progress.
077*/
078//public static final int SCROLL_STATE_IDLE = 0;
079/**
080* Indicates that the pager is currently being dragged by the user.
081*/
082//public static final int SCROLL_STATE_DRAGGING = 1;
083/**
084* Indicates that the pager is in the process of settling to a final position.
085*/
086//public static final int SCROLL_STATE_SETTLING = 2;
087
088}
089});
090
091}
092
093private class MyPagerAdapter extends PagerAdapter{
094
095@Override
096public void destroyItem(View arg0, int arg1, Object arg2) {
097Log.d("k", "destroyItem");
098((ViewPager) arg0).removeView(mListViews.get(arg1));
099}
100
101@Override
102public void finishUpdate(View arg0) {
103Log.d("k", "finishUpdate");
104}
105
106@Override
107public int getCount() {
108Log.d("k", "getCount");
109return mListViews.size();
110}
111
112@Override
113public Object instantiateItem(View arg0, int arg1) {
114Log.d("k", "instantiateItem");
115((ViewPager) arg0).addView(mListViews.get(arg1),0);
116return mListViews.get(arg1);
117}
118
119@Override
120public boolean isViewFromObject(View arg0, Object arg1) {
121Log.d("k", "isViewFromObject");
122return arg0==(arg1);
123}
124
125@Override
126public void restoreState(Parcelable arg0, ClassLoader arg1) {
127Log.d("k", "restoreState");
128}
129
130@Override
131public Parcelable saveState() {
132Log.d("k", "saveState");
133return null;
134}
135
136@Override
137public void startUpdate(View arg0) {
138Log.d("k", "startUpdate");
139}
140
141}
142
143 }
在实机上测试后,非常流畅,这也就是说官方版的左右滑屏控件已经实现
目前,关于viewpager的文章非常少,本文是通过阅读viewpager源代码分析出的写法
当然此文章仅是抛砖引玉,而且属于框架式程序,目的就是让读者了解API的基本用法
希望这篇原创文章对大家有帮助
欢迎感兴趣的朋友一起讨论
共同学习,共同进步
另外,ViewPager的注释上有这么一段话,大体意思是该控件目前属于早期实现,后续会有修改
01 /**
02* Layout manager that allows the user to flip left and right
03* through pages of data.You supply an implementation of a
04* {@link PagerAdapter} to generate the pages that the view shows.
05*
06* <p>Note this class is currently under early design and
07* development.The API will likely change in later updates of
08* the compatibility library, requiring changes to the source code
09* of apps when they are compiled against the newer version.</p>
10*/
摘自 图灵的梦