Android自定义控件5--轮播图广告ViewPager基本实现

            <
            RelativeLayout 
            xmlns:android
            ="http://schemas.android.com/apk/res/android"
            
    xmlns:tools
            ="http://schemas.android.com/tools"
            
    android:layout_width
            ="match_parent"
            
    android:layout_height
            ="match_parent"
            
    tools:context
            =".MainActivity"
            >
            <
            RelativeLayout
        
            android:layout_width
            ="match_parent"
            
        android:layout_height
            ="160dp"
            >
            <
            android.support.v4.view.ViewPager
            
            android:id
            ="@+id/viewpager"
            
            android:layout_width
            ="match_parent"
            
            android:layout_height
            ="match_parent"
            />
            <
            LinearLayout
            
            android:layout_width
            ="match_parent"
            
            android:layout_height
            ="40dp"
            
            android:layout_alignParentBottom
            ="true"
            
            android:background
            ="#66000000"
            
            android:gravity
            ="center_horizontal"
            
            android:orientation
            ="vertical"
            
            android:padding
            ="5dp"
            >
            <
            TextView
                
            android:layout_width
            ="wrap_content"
            
                android:layout_height
            ="wrap_content"
            
                android:singleLine
            ="true"
            
                android:text
            ="和谐社会，和谐社会，和谐社会，和谐社会"
            
                android:textColor
            ="@android:color/white"
            />
            <
            LinearLayout
                
            android:id
            ="@+id/ll_point_container"
            
                android:layout_width
            ="wrap_content"
            
                android:layout_height
            ="wrap_content"
            
                android:layout_marginTop
            ="5dp"
            
                android:orientation
            ="horizontal"
            >
            </
            LinearLayout
            >
            </
            LinearLayout
            >
            </
            RelativeLayout
            >
            </
            RelativeLayout
            >
        

            package
             com.wuyudong.viewpager;


            import
             java.util.ArrayList;


            import
             android.os.Bundle;

            import
             android.app.Activity;

            import
             android.support.v4.view.PagerAdapter;

            import
             android.support.v4.view.ViewPager;

            import
             android.view.Menu;

            import
             android.view.View;

            import
             android.view.ViewGroup;

            import
             android.widget.BaseAdapter;

            import
             android.widget.ImageView;


            public
            class MainActivity extends Activity {

    private ViewPager viewPager;
    privateint[] imageResIds;
    private ArrayList<ImageView> imageViewList;

    @Override
    protectedvoid onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // 初始化布局 View 视图        initViews();

        // Model 数据        initData();

        // Controller 控制器        initAdapter();

    }

    privatevoid initViews() {
        viewPager = (ViewPager) findViewById(R.id.viewpager);

        imageResIds = newint[] { R.drawable.a, R.drawable.b, R.drawable.c,
                R.drawable.d, R.drawable.e };
        imageViewList = new ArrayList<ImageView>();
        ImageView imageView;
        for (int i = 0; i < imageResIds.length; i++) {
            imageView = new ImageView(this);
            imageView.setBackgroundResource(imageResIds[i]);
            imageViewList.add(imageView);
        }
    }

    privatevoid initAdapter() {
        //
    }

    privatevoid initData() {
        // 初始化要显示的数据
        viewPager.setAdapter(new MyAdapter());

    }

    class MyAdapter extends PagerAdapter {

        @Override
        publicint getCount() {
            return imageViewList.size();
        }

        // 3、指定复用的判断逻辑        @Override
        publicboolean isViewFromObject(View view, Object object) {
            // 当滑到新的条目，又返回来，view是否可以被复用return view == object;
        }

        // 1、返回要显示的条目内容，创建条目        @Override
        public Object instantiateItem(ViewGroup container, int position) {
            // container：容器：ViewPager
            // position：当前要显示的条目的位置
            ImageView imageView = imageViewList.get(position);
            // a、把view对象添加到container中            container.addView(imageView);
            // b、把view对象返回给框架，适配器return imageView; // 必须要重写，否则抛异常        }

        // 2、销毁条目        @Override
        publicvoid destroyItem(ViewGroup container, int position, Object object) {
            // object 要销毁的对象            container.removeView((View) object);
        }

    }
}