自动滚动的ViewPager

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效果图：

这里写图片描述

使用方法：

AutoScrollViewPager viewPager = (AutoScrollViewPager) findViewById(R.id.vp_photos);viewPager.setDataList(mUrlList);viewPager.updateView(0);viewPager.setIsAutoScroll(true);viewPager.setIsShowDot(true);

步骤一：在value的attrs.xml文件里添加自定义样式

<?xml version="1.0" encoding="utf-8"?><resources>    <declare-styleable name="AutoScrollViewPager">        <attr name="autoscroll" format="boolean" />        <attr name="show_navgation_dot" format="boolean" />    </declare-styleable></resources>

步骤二：

添加 Android-Universal-Image-Loader Jar包（当然也可以用其他的加载网络图片工具）

这里写图片描述

步骤三：自定义view

/** * Created by pengkv on 15/12/5. */public class AutoScrollViewPager extends FrameLayout implements View.OnClickListener {    private Context mContext;    private List<String> mDataList;//图片地址集合    private int mBofPosition;    private boolean isShowDot;//是否显示小点    private boolean isAutoScroll;//是否自动滚动    private List<View> mViewList;    private ViewPager mViewPager;    private LinearLayout mDotLayout;//放置小点的容器    private MyPagerAdapter mPagerAdapter;    private ViewPagerRollHelper mRollHelper;//控制滚动的工具类    private ViewPager.LayoutParams mImageParams;//图片的布局参数    private LinearLayout.LayoutParams mDotParams;//小点的布局参数    private FrameLayout.LayoutParams mViewPagerParams;//ViewPager的布局参数    private FrameLayout.LayoutParams mDotLayoutParams;//放置小点容器的布局参数    public AutoScrollViewPager(Context context, AttributeSet attrs) {        this(context, attrs, 0);    }    public AutoScrollViewPager(Context context, AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);        mContext = context;        TypedArray array = mContext.obtainStyledAttributes(attrs, R.styleable.AutoScrollViewPager, defStyleAttr, 0);        isAutoScroll = array.getBoolean(R.styleable.AutoScrollViewPager_autoscroll, true);        isShowDot = array.getBoolean(R.styleable.AutoScrollViewPager_show_navgation_dot, true);        array.recycle();    }    public void setIsAutoScroll(boolean isAutoScroll) {        this.isAutoScroll = isAutoScroll;    }    public void setIsShowDot(boolean isShowDot) {        this.isShowDot = isShowDot;    }    public void setDataList(List<String> mDataList) {        this.mDataList = mDataList;        initView();    }    private void initView() {        mViewList = new ArrayList<>();        //初始化图片布局参数        mImageParams = new ViewPager.LayoutParams();        mImageParams.width = ViewGroup.LayoutParams.MATCH_PARENT;        mImageParams.height = ViewGroup.LayoutParams.MATCH_PARENT;        //初始化小点布局参数        int size = mContext.getResources().getDimensionPixelSize(R.dimen.five_dp);        mDotParams = new LinearLayout.LayoutParams(size, size);        mDotParams.setMargins(5, 0, 5, 0);        //初始化ViewPager布局参数        mViewPagerParams = new LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);        //初始化ViewPager        mPagerAdapter = new MyPagerAdapter(mViewList);        mViewPager = new ViewPager(mContext);        mViewPager.setLayoutParams(mViewPagerParams);        mViewPager.setAdapter(mPagerAdapter);        mViewPager.addOnPageChangeListener(new MyPagerOnScrollChangeListener());        //加载ViewPager        addView(mViewPager);        if (isShowDot) {            int height = mContext.getResources().getDimensionPixelOffset(R.dimen.twenty_dp);            mDotLayoutParams = new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, height);            mDotLayoutParams.gravity = Gravity.BOTTOM | Gravity.CENTER;            mDotLayout = new LinearLayout(mContext);            mDotLayout.setLayoutParams(mDotLayoutParams);            mDotLayout.setOrientation(LinearLayout.HORIZONTAL);            mDotLayout.setGravity(Gravity.CENTER);            addView(mDotLayout);        }    }    public void updateView(int position) {        if (null != mDotLayout) {            mDotLayout.removeAllViews();        }        if (null != mViewList) {            int length = mDataList.size();            int viewLength = mViewList.size();            for (int i = 0; i < length; i++) {                String imgUrl = mDataList.get(i);                ImageView view;                if (i < viewLength) {//取以前的View                    view = (ImageView) mViewList.get(i);                } else {//新增View                    view = new ImageView(mContext);                    view.setLayoutParams(mImageParams);                    mViewList.add(view);                }                view.setScaleType(ImageView.ScaleType.CENTER_CROP);                view.setOnClickListener(this);                //初始化加载图片框架                ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(mContext)                        .threadPriority(Thread.NORM_PRIORITY - 2)// 线程优先级                        .denyCacheImageMultipleSizesInMemory()                        .tasksProcessingOrder(QueueProcessingType.LIFO)                        .memoryCache(new LruMemoryCache(3 * 1024 * 1024))                        .memoryCacheSize(3 * 1024 * 1024)                        .build();                ImageLoader.getInstance().init(config);                //下载图片－－》这里可以替换成自己想要的加载图片工具                ImageLoader.getInstance().displayImage(imgUrl, view);                //添加小点视图                if (isShowDot) {                    ImageView dot = new ImageView(mContext);                    dot.setImageResource(R.drawable.dot);                    dot.setLayoutParams(mDotParams);                    if (i == 0)                        dot.setSelected(true);                    mDotLayout.addView(dot);                }            }            //控制ViewPager的滚动            setCurrentItem(position);            mPagerAdapter.notifyDataSetChanged();            mRollHelper = new ViewPagerRollHelper(mViewPager, mPagerAdapter);            mRollHelper.setAutoScroll(isAutoScroll);            mRollHelper.autoScroll();        }    }    public void setCurrentItem(int position) {        mViewPager.setCurrentItem(position);    }    public int getCurrentItem() {        return mViewPager.getCurrentItem();    }    @Override    public void onClick(View v) {    }    //ViewPager适配器：加载图片    private class MyPagerAdapter extends PagerAdapter {        private List<View> viewList;        public MyPagerAdapter(List<View> viewList) {            this.viewList = viewList;        }        @Override        public int getCount() {            return viewList.size();        }        @Override        public boolean isViewFromObject(View view, Object object) {            return view == object;        }        @Override        public void destroyItem(ViewGroup container, int position, Object object) {            container.removeView(viewList.get(position));        }        @Override        public Object instantiateItem(ViewGroup container, int position) {            View view = viewList.get(position);            container.addView(view);            return view;        }    }    //页面滚动监听器：主要是为了控制小点的显示    private class MyPagerOnScrollChangeListener implements ViewPager.OnPageChangeListener {        @Override        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {        }        @Override        public void onPageSelected(int position) {            mRollHelper.setPagerChangeEvent(position);            if (isShowDot) {                View view = mDotLayout.getChildAt(position);                View befView = mDotLayout.getChildAt(mBofPosition);                view.setSelected(true);                befView.setSelected(false);                mBofPosition = position;            }        }        @Override        public void onPageScrollStateChanged(int state) {        }    }}

步骤四：添加辅助类

/** * Created by pengkv on 15/12/5. */public class ViewPagerRollHelper {    private ViewPager mViewPager = null;    private PagerAdapter mPagerAdapter = null;    private int newPosition, oldPosition, maxPosition;    private boolean isAutoScroll = true;    private static final int CHANGE_ADS = 0;//切换的参数    private Timer mTimer = null;    private MyTimertask myTimertask = null;    public ViewPagerRollHelper(ViewPager viewPager, PagerAdapter pagerAdapter) {        mViewPager = viewPager;        mPagerAdapter = pagerAdapter;    }    //控制ViewPager的当前位置    Handler handler = new Handler() {        @Override        public void handleMessage(Message msg) {            super.handleMessage(msg);            switch (msg.what) {                case CHANGE_ADS:                    newPosition = (Integer) msg.obj;                    mViewPager.setCurrentItem(newPosition);                    break;            }        }    };    //自动滚动    public void autoScroll() {        //获取页面个数        maxPosition = mPagerAdapter.getCount() - 1;        if (isAutoScroll && maxPosition > 0) {            if (mTimer != null) {                mTimer.cancel();                mTimer = null;            }            mTimer = new Timer();            if (myTimertask != null) {                myTimertask.cancel();                myTimertask = null;            }            if (null == myTimertask)                myTimertask = new MyTimertask();            mTimer.schedule(myTimertask, 3000, 3000);        }    }    //设置页面变更事件    public void setPagerChangeEvent(int curIndex) {        newPosition = curIndex;        oldPosition = newPosition - 1;        autoScroll();    }    //发送位置变更信息    class MyTimertask extends TimerTask {        @Override        public void run() {            if (newPosition >= 0 && newPosition < maxPosition) {//自动翻下一页                newPosition += 1;            } else if (newPosition == maxPosition) {//在最后一页                newPosition = 0;            }            Message message = handler.obtainMessage();            message.what = CHANGE_ADS;            message.obj = newPosition;            handler.sendMessage(message);        }    }    public void setAutoScroll(boolean isAutoScroll) {        this.isAutoScroll = isAutoScroll;    }}

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