在复选框上更新列表项内容单击

Question

I have a custom listview with item layout having a checkbox at the left and 4 textviews much like astrid task manager.

What I intend to do is that on clicking the checkbox, the textviews have to update their values. At first, my problem was that on checking a checkbox at position 1 would check the checkbox at the end or somewhere else while scrolling. While searching for a solution, I came to know about recycling of view in listview. I applied those concepts like viewholder and right now I am able to maintain the state of checkbox. But, on checkbox click, I change the textviews and the change is not persisting, meaning any random tv also shows the same change.

I have applied a checkbox onclicklistener in my adapter. Any ideas how to achieve it?

Answer 1

You will want to persist the state of the item in your item data rather than in the view holder. The view holder is just a convenience to the view, which at various times will display many different items, assuming you recycle the views. During the data binding, you will want to bind all state necessary for displaying your item to avoid having random data appearing in another list item's view.

public class MyListAdapter extends BaseAdapter {

    // ....

    @Override
    View getView(final int position, View convertView, ViewGroup parent) {
        View view = convertView;
        if (view == null) {
            view = inflate(R.layout.my_list_item_layout, parent, false);

            // View holder just prevents having to look up these values 
            // every time the view is reused.
            MyViewHolder holder = new MyViewHolder();
            holder.checkbox = (CheckBox) view.findViewById(R.id.check_box);
            holder.textview = (TextView) view.findViewById(R.id.text_view);
            view.setTag(holder);
        }

        final MyViewHolder holder = (MyViewHolder) view.getTag();
        final MyData data = (MyData) getItem(position);
        holder.checkbox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                data.savedCheckboxState = isChecked;
                // now tell the view to rebind the data
                notifyDataSetChanged();
            }
        });

        holder.checkbox.setChecked(data.savedCheckboxState);
        holder.textview.setText(String.valueOf(data.savedCheckboxState));
        return view;
    }

    private static class MyViewHolder {
        CheckBox checkbox;
        TextView textview;
    }
}

Answer 2

You can refer to my full code here, what you can do is,store check box state in a boolean array then you wont face this issue.....

Android checkbox multiselected issue