像淘宝和京东都会有跑马灯的效果，今天给大家贡献下以前项目的一个demo，各位看官，且看效果图。
我们先定义一个Bean文件，这个实体类文件主要包含标题，内容描述，以及还有跳转的链接。
LampBean
public class LampBean implements Serializable {public String title;
public String info;
}
接下来我们要去自定义一个LampView了，Lamp主要实现数据的接受，适配器填充数据，以及滚动实现，这里可以看出适配器模式在我们Android开发模式中用处的广泛，为了方便后面的数据的适配我们将数据源用泛型。
public abstract class BaseAutoScrollTextView<T> extends ListView implementsAutoScrollData<T> {private ArrayList<T> mDataList = new ArrayList<T>();private float mSize=16;private int mMax;private int position = -1;private int scroll_Y;private int mScrollY;private AutoScrollAdapter mAutoScrollAdapter = new AutoScrollAdapter();private OnItemClickListener mOnItemClickListener;private long mTimer = 1000;private Context mContext;protected abstract int getAdertisementHeight();private Handler handler = new Handler();Runnable runnable = new Runnable() {@Overridepublic void run() {// 开启轮播switchItem();handler.postDelayed(this, mTimer);}};public interface OnItemClickListener {public void onItemClick(int position);}public BaseAutoScrollTextView(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);this.mContext = context;mScrollY = dip2px(getAdertisementHeight());init();}public BaseAutoScrollTextView(Context context, AttributeSet attrs) {this(context, attrs, 0);}public BaseAutoScrollTextView(Context context) {this(context, null);}private void init() {this.setDivider(null);this.setFastScrollEnabled(false);this.setDividerHeight(0);this.setEnabled(false);}private int dip2px(float dipValue) {final float scale = mContext.getResources().getDisplayMetrics().density;return (int) (dipValue * scale + 0.5f);}private void switchItem() {if (position == -1) {scroll_Y = 0;} else {scroll_Y = mScrollY;}smoothScrollBy(scroll_Y, 2000);setSelection(position);position++;}private class AutoScrollAdapter extends BaseAdapter {@Overridepublic int getCount() {final int count = mDataList == null ? 0 : mDataList.size();return count > 1 ? Integer.MAX_VALUE : count;}@Overridepublic Object getItem(int position) {return mDataList.get(position % mMax);}@Overridepublic long getItemId(int position) {return position % mMax;}@Overridepublic View getView(final int position, View convertView,ViewGroup parent) {ViewHolder viewHolder;if (null == convertView) {viewHolder = new ViewHolder();convertView = LayoutInflater.from(mContext).inflate(R.layout.item_lamp_layout, null);viewHolder.mTitleView = (TextView) convertView.findViewById(R.id.tv_title);viewHolder.mInfoView = (TextView) convertView.findViewById(R.id.tv_info);convertView.setTag(viewHolder);} else {viewHolder = (ViewHolder) convertView.getTag();}T data = mDataList.get(position % mMax);initItemData(position, convertView, viewHolder, data);return convertView;}}private void initItemData(final int position, View convertView, ViewHolder viewHolder, T data) {viewHolder.mTitleView.setLayoutParams(new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT,dip2px(getAdertisementHeight())));viewHolder.mTitleView.setTextSize(mSize);viewHolder.mInfoView.setTextSize(mSize);viewHolder.mTitleView.setText(getTextTitle(data));viewHolder.mInfoView.setText(getTextInfo(data));convertView.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {mOnItemClickListener.onItemClick(position % mMax);}});}static class ViewHolder {TextView mTitleView;// 标题TextView mInfoView;// 内容}@Overridepublic boolean onInterceptTouchEvent(MotionEvent ev) {return false;}public void setData(ArrayList<T> _datas) {mDataList.clear();mDataList.addAll(_datas);mMax = mDataList == null ? 0 : mDataList.size();this.setAdapter(mAutoScrollAdapter);mAutoScrollAdapter.notifyDataSetChanged();}public void setTextSize(float _size){this.mSize=_size;}public void setOnItemClickListener(OnItemClickListener _listener) {this.mOnItemClickListener = _listener;}public void setTimer(long _time) {this.mTimer = _time;}public void start() {handler.postDelayed(runnable, 1000);}public void stop() {handler.removeCallbacks(runnable);}}
然后添加一个实现的类：
public class VerticalLampView extendsBaseAutoScrollTextView<LampBean> {public VerticalLampView(Context context, AttributeSet attrs,int defStyle) {super(context, attrs, defStyle);}public VerticalLampView(Context context, AttributeSet attrs) {super(context, attrs);}public VerticalLampView(Context context) {super(context);}@Overridepublic String getTextTitle(LampBean data) {return data.title;}@Overridepublic String getTextInfo(LampBean data) {return data.info;}/** * 这里面的高度应该和你的xml里设置的高度一致 */@Overrideprotected int getAdertisementHeight() {return 40;}}
最后是测试代码：
public class LampView extends FrameLayout { @Bind(R.id.lamp_view) VerticalLampView lampView; private Context mContext = null; private List<LampBean> list=new ArrayList<>(); public LampView(Context context, AttributeSet attrs) { super(context, attrs); this.mContext = context; init(); } private void init() { setView(); } private void setView() { inflate(getContext(), R.layout.lamp_layout, this); ButterKnife.bind(this, this); initData(); initView(); } private void initView() { lampView.setData((ArrayList<LampBean>) list); lampView.setTextSize(15); lampView.setTimer(2000); lampView.start(); } private void initData() { LampBean bean = new LampBean(); bean.title = "爆款"; bean.info = "踏青零食上京东，百万零食1元秒"; list.add(bean); bean = new LampBean(); bean.title = "公告"; bean.info = "看老刘中国行，满129减50！"; list.add(bean); bean = new LampBean(); bean.title = "活动"; bean.info = "高姿CC霜全渠道新品首发，领券199减50，点击查看"; list.add(bean); }}
最后老规矩附上代码地址: