ViewPager

实现ViewPager滑动

（滑动但不循环）
1、创建一个Activity类
2、创建一个布局，里面有个ViewPager组件

<android.support.v4.view.ViewPager        android:id="@+id/viewPager"        android:layout_width="match_parent"        android:layout_height="match_parent" />

3、（一、得到组件）在Activity类里实例化组件，并引用上述布局

private ViewPager mViewPager;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_viewpager_layout);        mViewPager = (ViewPager) findViewById(R.id.viewPager);

4、（二、建立数据源）创建多个布局（ViewPager里的每一页的布局），在Activity里得到布局，并放入一个数列集合

View v1 = LayoutInflater.from(this).inflate(R.layout.activity_viewpager_item1_layout, null);View v2 = LayoutInflater.from(this).inflate(R.layout.activity_viewpager_item2_layout, null);View v3 = LayoutInflater.from(this).inflate(R.layout.activity_viewpager_item3_layout, null);ArrayList<View> arrayList = new ArrayList<View>();arrayList.add(v1);arrayList.add(v2);arrayList.add(v3);

5、（三、创建适配器）

//滑动不循环public class MyViewPagerAdapter2 extends PagerAdapter{        private ArrayList<View> arrayList = new ArrayList<View>();        private LayoutInflater layoutInflater;        public MyViewPagerAdapter2(Context context){            layoutInflater = LayoutInflater.from(context);        }        public void setData(ArrayList<View> arrayList){            this.arrayList = arrayList;            notifyDataSetChanged();        }        @Override        public int getCount() {            return arrayList.size();        }        @Override        public boolean isViewFromObject(View arg0, Object arg1) {            return arg0 == arg1;        }        @Override//实例一个View        public Object instantiateItem(ViewGroup container, int position) {            View v = arrayList.get(position);            container.addView(v);            return v;        }        @Override//销毁一个View        public void destroyItem(ViewGroup container, int position, Object object) {            View v = arrayList.get(position);            container.removeView(v);        }    }

6、ViewPager和适配器关联起来，并把数据源设置进去

MyViewPagerAdapter2 adapter = new MyViewPagerAdapter2(this);        adapter.setData(arrayList);        mViewPager.setAdapter(adapter);

（滑动循环）
1、在上述的Activity类的onCreate()方法中添加

int n = Integer.MAX_VALUE / 2 % arrayList.size();int itemPosition = Integer.MAX_VALUE / 2 -n;mViewPager.setCurrentItem(itemPosition);

2把适配器类换成下列这种

//滑动循环    public class MyViewPagerAdapter1 extends PagerAdapter{        private ArrayList<View> arrayList = new ArrayList<View>();        private LayoutInflater layoutInflater;        public MyViewPagerAdapter1(Context context){            layoutInflater = LayoutInflater.from(context);        }        public void setData(ArrayList<View> arrayList){            this.arrayList = arrayList;            notifyDataSetChanged();        }        @Override        public int getCount() {            return Integer.MAX_VALUE;        }        @Override        public boolean isViewFromObject(View arg0, Object arg1) {            return arg0 == arg1;        }        @Override//实例一个View        public Object instantiateItem(ViewGroup container, int position) {            position = position % arrayList.size();            View v = arrayList.get(position);            if (v.getParent() != null) {                container.removeView(v);            }            container.addView(v);            return v;        }        @Override//销毁一个View        public void destroyItem(ViewGroup container, int position, Object object) {        }    }

ViewPager组件的监听事件

//监听页面滚动组件        mViewPager.setOnPageChangeListener(new OnPageChangeListener() {            @Override//当前页面            public void onPageSelected(int arg0) {            }            @Override//页面正在滚动            public void onPageScrolled(int arg0, float arg1, int arg2) {            }            @Override//页面改变            public void onPageScrollStateChanged(int arg0) {            }        });

（自动循环滑动）
1、先按照上述写一个可以循环滑动的ViewPager
2、创建一个Handler消息机制来发送、处理消息

private static final int TITME = 2000; /** 循环时间 */private static final int MSG_NEXT_IMAGE = 1;/** 下一张图片 */private static final int MSG_PAGE_CHANGED = 2;/** 设置当前页号 */private Handler mPagerHandler = new Handler() {        boolean flag = true;        int currentPagerNo = 0; // 表示页号        public void handleMessage(android.os.Message msg) {            // 检查消息队列并移除未发送的消息，这主要是避免在复杂环境下消息出现重复等问题。//          if (mPagerHandler.hasMessages(MSG_NEXT_IMAGE) && !flag) {//              mPagerHandler.removeMessages(MSG_NEXT_IMAGE);//              flag = false;//          }            switch (msg.what) {            case MSG_NEXT_IMAGE:                currentPagerNo++;                mViewPager.setCurrentItem(currentPagerNo);                mPagerHandler.sendEmptyMessageDelayed(MSG_NEXT_IMAGE, TITME);                break;            case MSG_PAGE_CHANGED:                // 记录当前的页号，避免播放的时候页面显示不正确。                currentPagerNo = msg.arg1;                break;            }        }    };

3、在onCreate()方法中发送消息

mPagerHandler.sendEmptyMessageDelayed(MSG_NEXT_IMAGE, TITME);

4、监听ViewPager

mViewPager.setOnPageChangeListener(new OnPageChangeListener() {            @Override            public void onPageSelected(int postion) {                mPagerHandler.sendMessage(Message.obtain(mPagerHandler,MSG_PAGE_CHANGED, postion, 0));            }            @Override            public void onPageScrolled(int arg0, float arg1, int arg2) {            }            @Override            public void onPageScrollStateChanged(int arg0) {            }        });