How can I change the background color of Elevated Button in Flutter from function?

🎵 Change the background color of an Elevated Button in Flutter 🌈

Are you new to Flutter and looking to create a simple Xylophone application? You've come to the right place! In this guide, we'll show you how to change the background color of Elevated Buttons in Flutter and address the common issue you may encounter along the way.

The Error

Here's the error you might be facing when trying to call the playSound function:

type '_MaterialStatePropertyAll' is not a subtype of type 'MaterialStateProperty<Color?>?'

The Code

First, let's take a look at the code for the playSound function and the buildPlayButton method, where the error is occurring:

void playSound(int soundNumber) {
  final player = AudioCache();
  player.play('note$soundNumber.wav');
}

Expanded buildPlayButton({MaterialStateProperty color, int soundNumber}) {
  return Expanded(
    child: ElevatedButton(
      onPressed: () {
        playSound(soundNumber);
      },
      style: ButtonStyle(
        backgroundColor: color,
      ),
    ),
  );
}

The Solution

To solve this error, you need to provide a valid Color object instead of MaterialStateProperty in the buildPlayButton method. Here's how you can modify the code:

Expanded buildPlayButton({Color color, int soundNumber}) {
  return Expanded(
    child: ElevatedButton(
      onPressed: () {
        playSound(soundNumber);
      },
      style: ButtonStyle(
        backgroundColor: MaterialStateProperty.all(color),
      ),
    ),
  );
}

In the modified code, we replaced MaterialStateProperty with Color as a parameter for the buildPlayButton method. Additionally, we wrapped the color parameter with MaterialStateProperty.all to create a valid MaterialStateProperty<Color?> for the backgroundColor property.

After making these changes, you can call the buildPlayButton method with the desired color like this:

Widget build(BuildContext context) {
  return Column(
    crossAxisAlignment: CrossAxisAlignment.stretch,
    children: [
      buildPlayButton(color: Colors.red, soundNumber: 1),
      buildPlayButton(color: Colors.orangeAccent, soundNumber: 2),
      buildPlayButton(color: Colors.yellow, soundNumber: 3),
      buildPlayButton(color: Colors.indigo, soundNumber: 4),
      buildPlayButton(color: Colors.blue, soundNumber: 5),
      buildPlayButton(color: Colors.lightGreenAccent, soundNumber: 6),
      buildPlayButton(color: Colors.green, soundNumber: 7),
    ],
  );
}

Take It to the Next Level! ✨

Now that you've successfully changed the background color of Elevated Buttons in Flutter, why not explore further? Experiment with different colors and styles to personalize your Xylophone application even more.

Share your creations with us and let your imagination run wild! 🎉

If you have any other questions or need additional assistance, feel free to leave a comment below. Happy coding! 💻