ViewPager的使用方法和实现过程

看图先：

        

页面中填充内容是随机关键词飞入和飞出动画效果，随后会更新，现在请先无视吧

 

首先是 导入jar包   下载地址： android-support-v4.jar

 

 

布局文件里添加viewPager布局

 

<android.support.v4.view.ViewPager
    android:id="@+id/search_viewpager"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center" >
</android.support.v4.view.ViewPager>

再创建两个item布局用于填充在ViewPager里

 

然后就是Activity了，主要写了左右滑动切换页面，还有一个小图片随页面切换 位移的动画效果

 

public class SearchAllcityActivity extends Activity {

    private KeywordsFlow keywordsFlow;
    private ViewPager viewPager;
    private ImageView imageView;
    private List<View> lists = new ArrayList<View>();
    private ViewPagerAdapter adapter;
    private Bitmap cursor;
    private int offSet;
    private int currentItem;
    private Matrix matrix = new Matrix();
    private int bmWidth;
    private Animation animation;
    private Button shuaxin_sq, shuaxin_fl;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.search_allcity);

        // 随页面滑动图片
        imageView = (ImageView) findViewById(R.id.viewpaget_img);
        // 热门商圈和热门分类 页面添加到viewPager集合
        lists.add(getLayoutInflater().inflate(R.layout.search_hot_shangqu, null));
        lists.add(getLayoutInflater().inflate(R.layout.search_hot_fenlei, null));
        // 初始化滑动图片位置
        initeCursor();
        adapter = new ViewPagerAdapter(lists);
        viewPager = (ViewPager) findViewById(R.id.search_viewpager);
        viewPager.setAdapter(adapter);
        // ViewPager滑动监听器
        viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {

            @Override
            public void onPageSelected(int arg0) {
                // TODO Auto-generated method stub
                // 当滑动时，顶部的imageView是通过animation缓慢的滑动
                switch (arg0) {
                case 0:
                    if (currentItem == 1) {
                        animation = new TranslateAnimation(offSet * 2 + bmWidth, 0, 0,0);
                    } else if (currentItem == 2) {
                        animation = new TranslateAnimation(offSet * 4 + 2 * bmWidth, 0,0, 0);
                    }

                    break;
                case 1:
                    if (currentItem == 0) {
                        animation = new TranslateAnimation(0, offSet * 2 + bmWidth, 0,0);
                    } else if (currentItem == 2) {
                        animation = new TranslateAnimation(4 * offSet + 2 * bmWidth,offSet * 2 + bmWidth, 0, 0);
                    }


                    break;
                }
                currentItem = arg0;
                animation.setDuration(500);
                animation.setFillAfter(true);
                imageView.startAnimation(animation);

            }

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

            }

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

            }
        });

    }


    /**
     * 计算滑动的图片的位置
     */
    private void initeCursor() {
        cursor = BitmapFactory.decodeResource(getResources(),R.drawable.viewpager_img);
        bmWidth = cursor.getWidth();
        DisplayMetrics dm;
        dm = getResources().getDisplayMetrics();
        offSet = (dm.widthPixels - 2 * bmWidth) / 4;
        matrix.setTranslate(offSet, 0);
        imageView.setImageMatrix(matrix); // 需要iamgeView的scaleType为matrix
        currentItem = 0;
    }

}

public class SearchAllcityActivity extends Activity {private KeywordsFlow keywordsFlow;private ViewPager viewPager;private ImageView imageView;private List<View> lists = new ArrayList<View>();private ViewPagerAdapter adapter;private Bitmap cursor;private int offSet;private int currentItem;private Matrix matrix = new Matrix();private int bmWidth;private Animation animation;private Button shuaxin_sq, shuaxin_fl;public void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.search_allcity);// 随页面滑动图片imageView = (ImageView) findViewById(R.id.viewpaget_img);// 热门商圈和热门分类 页面添加到viewPager集合lists.add(getLayoutInflater().inflate(R.layout.search_hot_shangqu, null));lists.add(getLayoutInflater().inflate(R.layout.search_hot_fenlei, null));// 初始化滑动图片位置initeCursor();adapter = new ViewPagerAdapter(lists);viewPager = (ViewPager) findViewById(R.id.search_viewpager);viewPager.setAdapter(adapter);// ViewPager滑动监听器viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {@Overridepublic void onPageSelected(int arg0) {// TODO Auto-generated method stub// 当滑动时，顶部的imageView是通过animation缓慢的滑动switch (arg0) {case 0:if (currentItem == 1) {animation = new TranslateAnimation(offSet * 2 + bmWidth, 0, 0,0);} else if (currentItem == 2) {animation = new TranslateAnimation(offSet * 4 + 2 * bmWidth, 0,0, 0);}break;case 1:if (currentItem == 0) {animation = new TranslateAnimation(0, offSet * 2 + bmWidth, 0,0);} else if (currentItem == 2) {animation = new TranslateAnimation(4 * offSet + 2 * bmWidth,offSet * 2 + bmWidth, 0, 0);}break;}currentItem = arg0;animation.setDuration(500);animation.setFillAfter(true);imageView.startAnimation(animation);}@Overridepublic void onPageScrolled(int arg0, float arg1, int arg2) {// TODO Auto-generated method stub}@Overridepublic void onPageScrollStateChanged(int arg0) {// TODO Auto-generated method stub}});}/*** 计算滑动的图片的位置*/private void initeCursor() {cursor = BitmapFactory.decodeResource(getResources(),R.drawable.viewpager_img);bmWidth = cursor.getWidth();DisplayMetrics dm;dm = getResources().getDisplayMetrics();offSet = (dm.widthPixels - 2 * bmWidth) / 4;matrix.setTranslate(offSet, 0);imageView.setImageMatrix(matrix); // 需要iamgeView的scaleType为matrixcurrentItem = 0;}}

 

最后，不能忘了ViewPager的Adapter

 

 

public class ViewPagerAdapter extends PagerAdapter{

    List<View> viewLists;

    public ViewPagerAdapter(List<View> lists)
    {
        viewLists = lists;
    }

    @Override
    public int getCount() {                                                                 //获得size
        // TODO Auto-generated method stub
        return viewLists.size();
    }

    @Override
    public boolean isViewFromObject(View arg0, Object arg1) {
        // TODO Auto-generated method stub
        return arg0 == arg1;
    }

    @Override
    public void destroyItem(View view, int position, Object object)                       //销毁Item
    {
        ((ViewPager) view).removeView(viewLists.get(position));
    }

    @Override
    public Object instantiateItem(View view, int position)                                //实例化Item
    {
        ((ViewPager) view).addView(viewLists.get(position), 0);

        return viewLists.get(position);
    }

}