如何将listView中选中的item添加到ArrayList中？

Question

我有一个包含 12 个项目的 ListView，每个项目都包含一个 TextView 和一个复选框。我设法使 CheckBox 检查状态保持不变，这样当我上下滚动时，我不会丢失为每个 CheckBox 设置的检查状态。

我现在面临的问题是，对于 ListView 中的每个项目，如果其对应的 CheckBox 被选中，我想将 TextView 添加到 ArrayList，如果相应的 CheckBox 未被选中，我应该从中删除 TextView ArrayList如果包含在里面。

在下面的 getView() 方法代码中，行 "Log.d(TAG, "chosen topic size: " + chosenTopics.size());"总是 returns 零??!!

请帮我解决这个问题。

getView():

@Override
public View getView(final int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub
    View view = null;

    if (convertView == null) {
        LayoutInflater layoutinflater = (LayoutInflater) context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
        view = layoutinflater.inflate(R.layout.list_items_layout, null);

        final ViewHolder holder = new ViewHolder();

        holder.tv = (TextView) view.findViewById(R.id.tvlist_topic);
        holder.cb = (CheckBox) view.findViewById(R.id.cbList_hook);
        holder.iv = (ImageView) view.findViewById(R.id.ivList_delete);

        holder.cb.setOnCheckedChangeListener(new OnCheckedChangeListener() {

            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                // TODO Auto-generated method stub
                ItemDesign element = (ItemDesign) holder.cb.getTag();
                element.setChecked(buttonView.isChecked());

                if(element.isChecked()) {
                    if (!chosenTopics.contains(designList.get(position).getTopic()))
                        chosenTopics.add(designList.get(position).getTopic());
                }

                if (!element.isChecked()) {
                    if (!chosenTopics.isEmpty()) {
                    if (chosenTopics.contains(designList.get(position).getTopic()))
                        chosenTopics.remove(position);
                    }
                }
            }
        });

        Log.d(TAG, "chosen topic size: " + chosenTopics.size());
        view.setTag(holder);
        holder.cb.setTag(designList.get(position));

    } else {
        view = convertView;
        ((ViewHolder) view.getTag()).cb.setTag(designList.get(position));
    }

    final ViewHolder holder = (ViewHolder) view.getTag();
    holder.tv.setText(designList.get(position).getTopic());
    holder.cb.setChecked(designList.get(position).isChecked());

    holder.iv.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            if (holder.cb.isChecked())
                holder.cb.setChecked(false);

            designList.remove(position);
            notifyDataSetChanged();
        }
    });

    return view;
}

LogCat 将 ArrayList 的初始化移动到构造函数后出现错误:

02-12 14:40:14.117: E/AndroidRuntime(22500): FATAL EXCEPTION: main
02-12 14:40:14.117: E/AndroidRuntime(22500): Process:  
com.example.mqtt_designlayout_02, PID: 22500
02-12 14:40:14.117: E/AndroidRuntime(22500):   
java.lang.IndexOutOfBoundsException: Invalid index 1, size is 1
02-12 14:40:14.117: E/AndroidRuntime(22500):    at 
java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255)
02-12 14:40:14.117: E/AndroidRuntime(22500):    at 
java.util.ArrayList.remove(ArrayList.java:403)
02-12 14:40:14.117: E/AndroidRuntime(22500):    at

com.example.mqtt_designlayout_02.listviewadapter.ListViewAdapter$1.onCheckedChanged(ListViewAdapter.java:95)

Answer 1

getView() method, the line "Log.d(TAG, "chosen topic size: " + chosenTopics.size());" always returns zero??!!

因为在 getView 方法中初始化 chosenTopics ArrayList，所以当 ListView 滚动时 up/down chosenTopics 对象再次初始化。取决于调用 getView 方法的次数。

解决问题移动

this.chosenTopics = new ArrayList<String>();

Adapter 构造函数内部的行

如何将listView中选中的item添加到ArrayList中？

How to add the checked item in listView to ArrayList?

android

listview

android-listview

getview