（转载）PagerView实现翻页效果

现在很多应用都在第一次启动时提供一个简要的介绍，以左右滑动的效果来介绍应用的使用和基本情况。下面将实现一个简单的Demo

首先到SDK的extra目录下找到android-support-v4.jar

首先看一下工程结构：

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <android.support.v4.view.ViewPager
        android:id="@+id/guidePages"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

    <RelativeLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical" >

        <LinearLayout
            android:id="@+id/viewGroup"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:layout_marginBottom="15dp"
            android:gravity="center_horizontal"
            android:orientation="horizontal" >
        </LinearLayout>
    </RelativeLayout>

</FrameLayout>

然后新建page1.xml文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <ImageView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:background="@drawable/a" >
    </ImageView>

</LinearLayout>

page2.xml、page3.xml一样，只要改变图片路径就行

然后编辑Activity

public class ViewPagerActivity extends Activity {

    private ViewPager viewPager;
    private ArrayList<View> pageViews;
    private ViewGroup main;
    private ViewGroup group;
    private ImageView imageView;
    private ImageView[] imageViews;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        this.requestWindowFeature(Window.FEATURE_NO_TITLE);

        setContentView(R.layout.main);

        LayoutInflater inflater = getLayoutInflater();
        pageViews = new ArrayList<View>();
        pageViews.add(inflater.inflate(R.layout.page1, null));
        pageViews.add(inflater.inflate(R.layout.page2, null));
        pageViews.add(inflater.inflate(R.layout.page3, null));

        imageViews = new ImageView[pageViews.size()];

        main = (ViewGroup)inflater.inflate(R.layout.main, null);

        //group是底部导航小圆点的布局
        group = (ViewGroup)main.findViewById(R.id.viewGroup);

        viewPager = (ViewPager)main.findViewById(R.id.guidePages);

        for (int i = 0; i < pageViews.size(); i++) {
            imageView = new ImageView(ViewPagerActivity.this);
            imageView.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT));
            imageViews[i] = imageView;
            if (i == 0) {
                //默认选中第一张图片
                imageViews[i].setBackgroundResource(R.drawable.indicator_f);
            } else {
                imageViews[i].setBackgroundResource(R.drawable.indicator);
            }
            group.addView(imageViews[i]);
        }

        setContentView(main);

        viewPager.setAdapter(new ViewPagerAdapter());
        viewPager.setOnPageChangeListener(new ViewPagerChangeListener());

    }

    class ViewPagerAdapter extends PagerAdapter{

        @Override
        public int getCount() {
            return pageViews.size();
        }

        @Override
        public boolean isViewFromObject(View arg0, Object arg1) {
            return arg0 == arg1;
        }

        @Override
        public void destroyItem(View arg0, int arg1, Object arg2) {
            ((ViewPager) arg0).removeView(pageViews.get(arg1));
        }

        @Override
        public Object instantiateItem(View arg0, int arg1) {
            ((ViewPager) arg0).addView(pageViews.get(arg1));
            return pageViews.get(arg1);
        }

    }

    class ViewPagerChangeListener implements OnPageChangeListener
    {

        @Override
        public void onPageScrollStateChanged(int arg0) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onPageScrolled(int arg0, float arg1, int arg2) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onPageSelected(int position) {
            for (int i = 0; i < imageViews.length; i++) {
                imageViews[position].setBackgroundResource(R.drawable.indicator_f);
                if (position != i) {
                    imageViews[i].setBackgroundResource(R.drawable.indicator);
                }
            }
        }
    }
}

运行，效果图如下，不是很美观，实际使用替换图片就行，需要源码的童鞋可以联系我。我的新浪微博 唐韧_Ryan