title: Flutter: Change the background color of selected button in ListView.builder
body: <p>I have a list of items and default color.</p>
  <pre><code>List&lt;String&gt; items = ['A', 'B', 'C'];
  Color _color = Colors.transparent;
  </code></pre>
  <p>From my code, it changes all the background colors of the buttons.</p>
  <pre><code>ListView.builder(
    itemCount: items.length,
    itemBuilder: (context, index) {
  
      return ElevatedButton(
        style: ButtonStyle(backgroundColor: MaterialStateProperty.all(_color)),
        onPressed: () {
          setState(() {
            _color = Colors.blue;
          });
        },
        child: Text(items[index]),
      );
  
    },
  );
  </code></pre>
  <p>So, I want only the selected button to change the background color.</p>