《最近做一個小功能遇到這么一個問題,listview 與 baseadapter結(jié)合使用,關(guān)于點贊的的時候 圖片重復問題,比如:我在第1個item 點贊然后 心型換成了紅色,但是以后每隔幾個item就會出現(xiàn)一個紅色的心,響應事件是對的,不知道哪出的問題,請大神解答”》
上面是一小哥在論壇中發(fā)的帖子遇到的問題,跟我遇到的問題一樣,下面有很多熱心的評論哥們給出了思路,我一想,原來這么簡單啊。
先給出實現(xiàn)代碼,最后再來講思路好了。
這篇博客我重新編輯了一次,加上了動畫和收藏的效果,評論的哥們說收藏和點贊不能同時進行,圖片會錯亂,我給了他思路,他還是沒實現(xiàn),哎,我還是再來一遍,修改修改吧,博主真是關(guān)心大家啊
效果圖

MainActivity.java
public class MainActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //模擬的數(shù)據(jù)內(nèi)容集合 List<ContentBean> data = new ArrayList<ContentBean>(); for (int i = 0; i < 15; i++) { ContentBean bean = new ContentBean(); // 默認都給他們賦值當前都沒有點贊 bean.setZanFocus(false); bean.setZanNum(i); // 默認都給他們賦值當前都沒有收藏 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" > <ListView android: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; } @Override public int getCount() { return data.size();// 返回20條數(shù)據(jù) } @Override public Object getItem(int arg0) { return data.get(arg0); } @Override public long getItemId(int position) { // TODO Auto-generated method stub return position; } @Override public 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中當記錄狀態(tài)是否為true,是的話則給img設(shè)置focus點贊圖片 if (bean.isZanFocus()) { holder.zan_img.setImageResource(R.drawable.zan_focus); } else { holder.zan_img.setImageResource(R.drawable.zan_release); } // 取出bean中當記錄狀態(tài)是否為true,是的話則給img設(shè)置release收藏圖片 if (bean.isShoucanFocus()) { holder.shoucan_img.setImageResource(R.drawable.shoucang_focus); } else { holder.shoucan_img.setImageResource(R.drawable.shoucang_release); } // 設(shè)置贊的數(shù)量 holder.zan_num.setText(bean.getZanNum() + ""); //設(shè)置收藏的數(shù)量 holder.shoucan_num.setText(bean.getShoucanNum()+""); holder.zan_img.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // 獲取上次是否已經(jīng)被點擊 boolean flag = bean.isZanFocus(); // 判斷當前flag是點贊還是取消贊,是的話就給bean值減1,否則就加1 if (flag) { bean.setZanNum(bean.getZanNum() - 1); } else { bean.setZanNum(bean.getZanNum() + 1); } // 反向存儲記錄,實現(xiàn)取消點贊功能 bean.setZanFocus(!flag); AnimationTools.scale(holder.zan_img); } }); holder.shoucan_img.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // 獲取上次是否已經(jīng)被點擊 boolean flag = bean.isShoucanFocus(); // 判斷當前flag是收藏還是取收藏,是的話就給bean值減1,否則就加1 if (flag) { bean.setShoucanNum(bean.getShoucanNum() - 1); } else { bean.setShoucanNum(bean.getShoucanNum() + 1); } // 反向存儲記錄,實現(xiàn)取消收藏功能 bean.setShoucanFocus(!flag); //動畫 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" > <ImageView android:id="@+id/zan_img" android:layout_width="wrap_content" android:layout_height="wrap_content" /> <TextView android: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); }}代碼其實很簡單,稍作理解還是很容易弄懂的,我們在listview更新item中的數(shù)據(jù)的時候,一定要明白一個道理,不要在item的view中直接更改數(shù)據(jù)(剛開始做的時候我就是直接holder.zan_img.setImageResource(資源圖片),發(fā)現(xiàn)往下滑動的時候,上一次的觸摸記錄被下面的item給復用了,造成了數(shù)據(jù)的混亂),不然會造成數(shù)據(jù)的混亂,要是明白的listview的工作原理的話,可能會更清楚的明白,listview每次加載的數(shù)據(jù)是當前屏幕的一屏數(shù)據(jù)(其實我了解的不多,但是在打印log的時候,發(fā)現(xiàn)log出來初始化的數(shù)據(jù)就是一屏的數(shù)據(jù)),當你如果直接去改變view的樣式的話,你觸摸的當前item會被下面還未出現(xiàn)的item給復用掉,我是這樣理解的=-=。
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