用ViewPager实现欢迎引导页面

ViewPager需要android-support-v4.jar这个包的支持，来自google提供的一个附加包。大家搜下即可。

ViewPager主要用来组织一组数据，并且通过左右滑动的方式来展示。

现在的大多数应用都会有一个欢迎引导页面，如图所示，通过左右滑动来告知用户一些功能特性。

 

 

这个引导图效果用ViewPager可以很轻松的实现。

正如前面所说，ViewPager是用来展示一组数据的，所以肯定需要Adapter来绑定数据和view。先写一个Adapter：

1、  布局界面比较简单，加入ViewPager组件，以及底部的引导小点：

 

2、其中小点的图片用一个selector来控制颜色（设置item的enable为true或者false）

dot.xml: 

 

 

3、  java文件

import java.util.ArrayList;

import java.util.List;

 

import android.app.Activity;

import android.os.Bundle;

import android.os.Parcelable;

importandroid.support.v4.view.PagerAdapter;

importandroid.support.v4.view.ViewPager;

importandroid.support.v4.view.ViewPager.OnPageChangeListener;

import android.view.View;

importandroid.view.View.OnClickListener;

import android.widget.ImageView;

import android.widget.LinearLayout;

 

public class WelcomeActivity extends Activity implementsOnClickListener, OnPageChangeListener{

     private ViewPager vp;

        private ViewPagerAdapter vpAdapter;

        private List<View> views;

       

        //引导图片资源

        private static final int[] pics = { R.drawable.whatsnew_00,

                R.drawable.whatsnew_01, R.drawable.whatsnew_02,

                R.drawable.whatsnew_03 };

       

        //底部小店图片

        private ImageView[] dots ;

       

        //记录当前选中位置

        private int currentIndex;

       

       

        @Override

        public void onCreate(Bundle savedInstanceState) {

            super.onCreate(savedInstanceState);

            setContentView(R.layout.main);

           

            views = new ArrayList<View>();

          

            LinearLayout.LayoutParams mParams =newLinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,

                    LinearLayout.LayoutParams.WRAP_CONTENT);

           

            //初始化引导图片列表

            for(int i=0; i<pics.length; i++) {

                ImageView iv = new ImageView(this);

                iv.setLayoutParams(mParams);

                iv.setImageResource(pics[i]);

                views.add(iv);

            }

            vp = (ViewPager) findViewById(R.id.viewpager);

            //初始化Adapter

            vpAdapter = new ViewPagerAdapter(views);

            vp.setAdapter(vpAdapter);

            //绑定回调

            vp.setOnPageChangeListener(this);

           

            //初始化底部小点

            initDots();

           

        }

       

        private void initDots() {

            LinearLayout ll = (LinearLayout) findViewById(R.id.ll);

          

 

            dots = new ImageView[pics.length];

 

            //循环取得小点图片

            for (int i = 0; i < pics.length; i++) {

            //得到一个LinearLayout下面的每一个子元素

                dots[i] = (ImageView) ll.getChildAt(i);

                dots[i].setEnabled(true);//都设为灰色

                dots[i].setOnClickListener(this);

                dots[i].setTag(i);//设置位置tag，方便取出与当前位置对应

            }

 

            currentIndex = 0;

            dots[currentIndex].setEnabled(false);//设置为白色，即选中状态

        }

       

       

        private void setCurView(int position)

        {

            if (position < 0 || position >= pics.length) {

                return;

            }

 

            vp.setCurrentItem(position);

        }

 

       

        private void setCurDot(int positon)

        {

            if (positon < 0 || positon > pics.length - 1 || currentIndex == positon) {

                return;

            }

 

            dots[positon].setEnabled(false);

            dots[currentIndex].setEnabled(true);

 

            currentIndex = positon;

        }

 

        //当滑动状态改变时调用

        @Override

        public void onPageScrollStateChanged(int arg0) {

            // TODO Auto-generated method stub

           

        }

 

        //当当前页面被滑动时调用

        @Override

        public void onPageScrolled(int arg0, float arg1, int arg2) {

            // TODO Auto-generated method stub

           

        }

 

        //当新的页面被选中时调用

        @Override

        public void onPageSelected(int arg0) {

            //设置底部小点选中状态

            setCurDot(arg0);

        }

 

        @Override

        public void onClick(View v) {

            int position = (Integer)v.getTag();

            setCurView(position);

            setCurDot(position);

        }

    public class ViewPagerAdapter extends PagerAdapter{

       

        //界面列表

        private List<View> views;

       

        public ViewPagerAdapter (List<View> views){

            this.views = views;

        }

 

        //销毁arg1位置的界面

        @Override

        public void destroyItem(View arg0, int arg1, Object arg2) {

            ((ViewPager) arg0).removeView(views.get(arg1));       

        }

 

        @Override

        public void finishUpdate(View arg0) {

            // TODO Auto-generated method stub

           

        }

 

        //获得当前界面数

        @Override

        public int getCount() {

            if (views != null)

            {

                return views.size();

            }

           

            return 0;

        }

       

 

        //初始化arg1位置的界面

        @Override

        public Object instantiateItem(View arg0, int arg1) {

           

            ((ViewPager) arg0).addView(views.get(arg1), 0);

           

            return views.get(arg1);

        }

 

        //判断是否由对象生成界面

        @Override

        public boolean isViewFromObject(View arg0, Object arg1) {

            return (arg0 == arg1);

        }

 

        @Override

        public void restoreState(Parcelable arg0, ClassLoader arg1) {

            // TODO Auto-generated method stub

           

        }

 

        @Override

        public Parcelable saveState() {

            // TODO Auto-generated method stub

            return null;

        }

 

        @Override

        public void startUpdate(View arg0) {

            // TODO Auto-generated method stub

           

        }

 

    }

转自：http://blog.csdn.net/t80t90s/article/details/7941432