android - How to change background color of selected items in ListView?

Question

i've seen many simillar questions and every answer is very specific to the problem and no straight forward answer, or i found tutorials that show how to create a checkbox that's checked on selected items. And i'm having trouble understanding how to do it from those codes.

I am following a tutorial found Here, and that's preaty much how my code looks only different names.

I Want to have a multipile selection ListView, when an item selected the background color is changed to mark the items i've selected.

Maybe i can acomplish this using a custom selector? I understood the common way is to save the positions of selected and do something in the getView function. I saw people creating ViewHolder, but i didn't really understand what it has to do with anything. Can someone please help me?

Thank in advance, Eric

Answer 1

Well i finally solved it, hope this helps someone :

What i did was created an ArrayList<Integer> that stores all the position of selected items, and toggle the background colors on clicks.

In my Adapter i define:

public ArrayList<Integer> selectedIds = new ArrayList<Integer>();

With the following method :

    public void toggleSelected(Integer position)
{
    if(selectedIds.contains(position))
    {
        selectedIds.remove(position);


    }
    else
    {
        selectedIds.add(position);
    }
}

which addes emoves items from the ArrayList

In my getView method :

            if (selectedIds.contains(position)) {
            convertView.setSelected(true);
            convertView.setPressed(true);
            convertView.setBackgroundColor(Color.parseColor("#FF9912"));
        }
        else
        {
            convertView.setSelected(false);
            convertView.setPressed(false);
            convertView.setBackgroundColor(Color.parseColor("#000000"));
        }

This checks if the position is storred in the ArrayList. if it does, paint it as selected. if not, the opposite.

all is left is the OnItemClick listener, i added :

    ((YourAdapter)list.getAdapter()).toggleSelected(new Integer(position));

When YourAdapter is the adapter of your ListView

Hope this helps anyone, as it's a generic answer :)