Question

Can someone explain this issue to me ?

I have a listview that holds more rows than the screen can show, so scrolling.
If I click on one item, I replace an icon that is part of each row. That all works.

The issue I have is that when I click on lets say the first item, I change the icon for that first row. When I now scroll down I see that the first row outside the visible viewport also changed the icon.

Why is that happening and how can I avoid this issue ?

Thanks in advance,
Mozzak

Answer 1

Just to make sure, you are using a class that implements ListAdapter or extends some other sort of adapter right?

When using an adapter, you will have to keep in mind that the views in the ListView are recycled to save memory. Because of this, you will need to store the state in a separate variable.

public View getView(int position, View convertView, ViewGroup parent) {
    if (convertView == null)
    {
        LayoutInflater inflator = (LayoutInflater)parent.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView = inflator.inflate(R.layout.listitem, null);
    }

    // Retreive my image that may or may not change
    ImageView myIcon = (ImageView) convertView.findViewById(R.id.iconView);

    // Checking my stored boolean for this position to see if I need to use icon2 or icon
    if (myItem[position].needsIconChanged)
    {
        // I have set my boolean, so use icon2
        myIcon.setImageResource(R.drawable.icon2);
    }
    else
    {
        // I have not set my boolean, or set it to false so set it to icon
        myIcon.setImageResource(R.drawable.icon);
    }

    return convertView;
}

You will also have to remember to set that boolean in your onItemCLick

public void onItemClick(AdapterView<?> myAdapter, View myView, int position, long arg3) {
    // Retreive your item and set a boolean or icon state (depending on what you do)
    myAdapter.getItemAtPosition(position).needsIconChanged = true;
}