Android_RecyclerView实现上下滚动广告条实例(带图片)
前言
公司新项目首页有个类似京东/淘宝滚动广告条,查了一下大概都是两种实现方式,一是textview,如果只有文字的话是可行的,但我们这个上面还有个小图片,所以pass;二是两个viewGroup,使用动画交替滚动,可以实现,就是显得很麻烦,于是偷懒的我就想着用recyclerView来解决这个小问题!
思路
这个滚动广告条高度通常是固定的,用一个固定高度的viewGroup来包裹一个recyclerView,recylerView的item布局设置一个minHeight为viewGroup的高度,这样刚好能看到一个完整的item,然后使用recyclerView自带的方法 smoothScrollBy()来滚动recyclerView;他需要两个参数,x轴的滚动距离和y轴的滚动距离,我们是上下滚动,所以x轴传入1就好啦!y轴距离传入你的item高度,然后使用handler写一个循环任务就可以实现一直滚动啦!
/** * Animate a scroll by the given amount of pixels along either axis. * * @param dx Pixels to scroll horizontally * @param dy Pixels to scroll vertically */ public void smoothScrollBy(int dx, int dy) { smoothScrollBy(dx, dy, null); }
遇到的问题
写好之后发现这个控件是不能够触摸滑动的,但是又需要点击事件。想了想如果在onTouchEvent之类的方法中处理的话很麻烦,还不能保证完全禁止一点点都不能滑,所以就又想了个偷懒的办法。给recyclerView上加一层透明的蒙板,彻底禁用掉recyclerView的touch事件,给蒙板设置点击事件……下面是代码
布局:
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="60dp" android:background="@color/colorWhite" android:orientation="horizontal"> <TextView android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_marginLeft="18dp" android:gravity="center" android:text="养车\n宝典" android:textColor="@color/colorTitle" android:textSize="12sp"/> <View android:layout_width="0.5dp" android:layout_height="match_parent" android:layout_marginBottom="12dp" android:layout_marginLeft="10dp" android:layout_marginTop="12dp" android:background="@color/colorTitle"/> <!--禁用了recyclerView的触摸事件,他的点击事件交由一个透明的蒙版来实现--> <RelativeLayout android:layout_marginLeft="6dp" android:layout_width="match_parent" android:layout_height="match_parent"> <com.xinshiwi.mycar.view.AutoScrollRecyclerView android:id="@+id/rv_home_maintain" android:layout_width="match_parent" android:layout_height="match_parent"/> <View android:id="@+id/view_home_maintain" android:layout_width="match_parent" android:layout_height="match_parent" android:background="@android:color/transparent"/> </RelativeLayout> </LinearLayout>
Adapter:
public class MaintainInfoAdapter extends RecyclerView.Adapter<MaintainInfoAdapter.MyViewHolder> { List<String> list; public MaintainInfoAdapter(List<String> list) { this.list = list; } @Override public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_home_maintain, null); return new MyViewHolder(view); } @Override public void onBindViewHolder(MyViewHolder holder, int position) { holder.tv.setText(list.get(position % 4)); } @Override public int getItemCount() { return Integer.MAX_VALUE; } public static class MyViewHolder extends RecyclerView.ViewHolder { public TextView tv; public MyViewHolder(View itemView) { super(itemView); tv = (TextView) itemView.findViewById(R.id.tv_maintain); } } }
设置recyclerView:
/** * 滚动养车宝典 */ private void initMaintainData() { mList = new ArrayList<>(); mList.add("如何做好队汽车的轮胎养护0"); mList.add("如何做好队汽车的轮胎养护1"); mList.add("如何做好队汽车的轮胎养护2"); mList.add("如何做好队汽车的轮胎养护3"); mRvHomeMaintain.setLayoutManager(new LinearLayoutManager(mActivity)); mAdapter = new MaintainInfoAdapter(mList); mRvHomeMaintain.setAdapter(mAdapter); Message msg = new Message(); msg.what = MAINTAIN_INFO; sHandler.sendMessageDelayed(msg, 3000); //通过一个透明的蒙板来设置点击事件 mViewHomeMaintain.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Toast.makeText(mActivity, "pos % 4:" + (pos % 4), Toast.LENGTH_SHORT).show(); } }); } //当前显示的item private int pos = 0; private Handler sHandler = new Handler() { @Override public void handleMessage(Message msg) { super.handleMessage(msg); switch (msg.what) { case MAINTAIN_INFO: mRvHomeMaintain.smoothScrollBy(0, SizeUtils.dp2px(60)); pos++; Message message = new Message(); message.what = MAINTAIN_INFO; sHandler.removeMessages(MAINTAIN_INFO); sHandler.sendMessageDelayed(message, 3000); break; } } };
只是一个小demo,很多细节没太考虑……有什么问题还望大佬们指出,不胜感激,也希望大家多多支持我们。
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