Android Listview点赞问题关于图片重复问题

public class MainActivity extends Activity {  @Override  protected 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" >  <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条数据  }  @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() {      @Override      public 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1        if (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() {      @Override      public 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1        if (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" >  <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);  }}