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《最近做一个小功能遇到这么一个问题,listview 与 baseadapter结合使用,关于点赞的的时候 图片重复问题,比如:我在第1个item 点赞然后 心型换成了红色,但是以后每隔几个item就会出现一个红色的心,响应事件是对的,不知道哪出的问题,请大神解答”》

上面是一小哥在论坛中发的帖子遇到的问题,跟我遇到的问题一样,下面有很多热心的评论哥们给出了思路,我一想,原来这么简单啊。
先给出实现代码,最后再来讲思路好了。
这篇博客我重新编辑了一次,加上了动画和收藏的效果,评论的哥们说收藏和点赞不能同时进行,图片会错乱,我给了他思路,他还是没实现,哎,我还是再来一遍,修改修改吧,博主真是关心大家啊
效果图


MainActivity.java

public class MainActivity extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);//模拟的数据内容集合List<ContentBean> data = new ArrayList<ContentBean>();for (int i = 0; i < 15; i++) {ContentBean bean = new ContentBean();// 默认都给他们赋值当前都没有点赞bean.setZanFocus(false);bean.setZanNum(i);// 默认都给他们赋值当前都没有收藏bean.setShoucanFocus(false);bean.setShoucanNum(i);data.add(bean);}ListView listview = (ListView) findViewById(R.id.listview);listview.setAdapter(new MyAdapter(this,data));}main.xml<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="com.example.zan.MainActivity" ><ListViewandroid:id="@+id/listview"android:layout_width="match_parent"android:layout_height="match_parent" ></ListView></RelativeLayout>ContentBean.javapublic class ContentBean {private boolean zanFocus, shoucanFocus;private int zanNum, shoucanNum;public boolean isShoucanFocus() {return shoucanFocus;}public void setShoucanFocus(boolean shoucanFocus) {this.shoucanFocus = shoucanFocus;}public int getShoucanNum() {return shoucanNum;}public void setShoucanNum(int shoucanNum) {this.shoucanNum = shoucanNum;}public boolean isZanFocus() {return zanFocus;}public void setZanFocus(boolean zanFocus) {this.zanFocus = zanFocus;}public int getZanNum() {return zanNum;}public void setZanNum(int zanNum) {this.zanNum = zanNum;}}MyAdapter.javapublic class MyAdapter extends BaseAdapter {List<ContentBean> data = new ArrayList<ContentBean>();Context context;public MyAdapter(Context context, List<ContentBean> data) {this.context = context;this.data = data;}@Overridepublic int getCount() {return data.size();// 返回20条数据}@Overridepublic Object getItem(int arg0) {return data.get(arg0);}@Overridepublic long getItemId(int position) {// TODO Auto-generated method stubreturn position;}@Overridepublic View getView(final int position, View convertView, ViewGroup parent) {final ViewHolder holder;final ContentBean bean = data.get(position);if (convertView == null) {convertView = LayoutInflater.from(context).inflate(R.layout.item,parent, false);holder = new ViewHolder();holder.zan_img = (ImageView) convertView.findViewById(R.id.zan_img);holder.zan_num = (TextView) convertView.findViewById(R.id.zan_num);holder.shoucan_img = (ImageView) convertView.findViewById(R.id.shoucan_img);holder.shoucan_num = (TextView) convertView.findViewById(R.id.shoucan_num);convertView.setTag(holder);} else {holder = (ViewHolder) convertView.getTag();}// 取出bean中当记录状态是否为true,是的话则给img设置focus点赞图片if (bean.isZanFocus()) {holder.zan_img.setImageResource(R.drawable.zan_focus);} else {holder.zan_img.setImageResource(R.drawable.zan_release);}// 取出bean中当记录状态是否为true,是的话则给img设置release收藏图片if (bean.isShoucanFocus()) {holder.shoucan_img.setImageResource(R.drawable.shoucang_focus);} else {holder.shoucan_img.setImageResource(R.drawable.shoucang_release);}// 设置赞的数量holder.zan_num.setText(bean.getZanNum() + "");//设置收藏的数量holder.shoucan_num.setText(bean.getShoucanNum()+"");holder.zan_img.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {// 获取上次是否已经被点击boolean flag = bean.isZanFocus();// 判断当前flag是点赞还是取消赞,是的话就给bean值减1,否则就加1if (flag) {bean.setZanNum(bean.getZanNum() - 1);} else {bean.setZanNum(bean.getZanNum() + 1);}// 反向存储记录,实现取消点赞功能bean.setZanFocus(!flag);AnimationTools.scale(holder.zan_img);}});holder.shoucan_img.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {// 获取上次是否已经被点击boolean flag = bean.isShoucanFocus();// 判断当前flag是收藏还是取收藏,是的话就给bean值减1,否则就加1if (flag) {bean.setShoucanNum(bean.getShoucanNum() - 1);} else {bean.setShoucanNum(bean.getShoucanNum() + 1);}// 反向存储记录,实现取消收藏功能bean.setShoucanFocus(!flag);//动画AnimationTools.scale(holder.shoucan_img);}});return convertView;}private class ViewHolder {private ImageView zan_img,shoucan_img;private TextView zan_num,shoucan_num;}}item.xml<?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="50dp"android:gravity="center"android:orientation="horizontal" ><ImageViewandroid:id="@+id/zan_img"android:layout_width="wrap_content"android:layout_height="wrap_content" /><TextViewandroid:id="@+id/zan_num"android:layout_width="wrap_content"android:layout_height="wrap_content"/></LinearLayout>AnimationTools.javapublic class AnimationTools {public static void scale(View v) {ScaleAnimation anim = new ScaleAnimation(1.0f, 1.5f, 1.0f, 1.5f,Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF,0.5f);anim.setDuration(300);v.startAnimation(anim);}}
代码其实很简单,稍作理解还是很容易弄懂的,我们在listview更新item中的数据的时候,一定要明白一个道理,不要在item的view中直接更改数据(刚开始做的时候我就是直接holder.zan_img.setImageResource(资源图片),发现往下滑动的时候,上一次的触摸记录被下面的item给复用了,造成了数据的混乱),不然会造成数据的混乱,要是明白的listview的工作原理的话,可能会更清楚的明白,listview每次加载的数据是当前屏幕的一屏数据(其实我了解的不多,但是在打印log的时候,发现log出来初始化的数据就是一屏的数据),当你如果直接去改变view的样式的话,你触摸的当前item会被下面还未出现的item给复用掉,我是这样理解的=-=。