• 吴裕雄--天生自然ANDROID开发学习:2.4.8 ListView之checkbox错位问题解决


    1.问题发生的原因:
    这是网上找来的一幅关于ListView getView方法调用机制的一个图
    

     

    2.解决方法示例:
    好的存储这个Checkbox的方法有很多,你可以放到一个HashMap<Integer, Boolean>中, 每次初始化的时候根据postion取出对应的boolean值,然后再进行checkbox的状态设置;也可以在entity类中加入了一个boolean值用于判断。
    Entity类:Person.java:
    
    public class Person implements Serializable{
        private String name;
        private String number;
        private boolean checkStatus;
        
        public Person(String name, String number) {
            super();
            this.name = name;
            this.number = number;
            this.checkStatus = false;
        }
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
        public String getNumber() {
            return number;
        }
    
        public void setNumber(String number) {
            this.number = number;
        }
    
        public boolean getCheckStatus() {
            return checkStatus;
        }
    
        public void setCheckStatus(boolean checkStatus) {
            this.checkStatus = checkStatus;
        }
        
    }
    实现的Adapter类:ContactListAdapter.java:
    
    public class ContactListAdapter extends BaseAdapter implements CompoundButton.OnCheckedChangeListener{
    
        private List<Person> mData;
        private Context mContext;
    
        public ContactListAdapter(List<Person> data, Context context) {
            mData = data;
            mContext = context;
        }
    
        // 定义一个刷新数据的方法
        public void changeData(List<Person> data) {
            mData = data;
            notifyDataSetChanged();
        }
    
        @Override
        public int getCount() {
            return mData.size();
        }
    
        @Override
        public Person getItem(int position) {
            return mData.get(position);
        }
    
        @Override
        public long getItemId(int position) {
            return position;
        }
    
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            final int index = position;
            ViewHolder viewHolder;
            if (convertView == null) {
                convertView = LayoutInflater.from(mContext).inflate(
                        R.layout.item_contact, parent, false);
                viewHolder = new ViewHolder();
                viewHolder.ly = (RelativeLayout) convertView
                        .findViewById(R.id.lyContactListItem);
                viewHolder.txtName = (TextView) convertView
                        .findViewById(R.id.txtName);
                viewHolder.txtNumber = (TextView) convertView
                        .findViewById(R.id.txtNumber);
                viewHolder.cbxStatus = (CheckBox) convertView
                        .findViewById(R.id.cbxStatus);
                convertView.setTag(viewHolder);
                viewHolder.cbxStatus.setTag(index);
            } else {
                viewHolder = (ViewHolder) convertView.getTag();
            }
            viewHolder.cbxStatus.setOnCheckedChangeListener(this);
            viewHolder.cbxStatus.setChecked(mData.get(position).getcheckStatus());
            viewHolder.txtName.setText(mData.get(index).getName());
            viewHolder.txtNumber.setText(mData.get(index).getNumber());
            return convertView;
        }
    
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            int index = (int)buttonView.getTag();
            if (isChecked)
                mData.get(index).setCheckStatus(true);
            else
                mData.get(index).setCheckStatus(false);
        }
    
    
        private class ViewHolder {
            RelativeLayout ly;
            TextView txtName;
            TextView txtNumber;
            CheckBox cbxStatus;
        }
    }
    另外别忘了一点: checkbox监听器的方法要添加在初始化Checkbox状态的代码之前
    

      

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  • 原文地址:https://www.cnblogs.com/tszr/p/13581828.html
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