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Warnings after upgrading to Flutter 3.27.0: 'value' and 'green' are deprecated

After upgrading Flutter to version 3.27.0, I started seeing some warnings related to deprecated properties in the Color class:

Warning:

info: 'value' is deprecated and shouldn't be used. Use component accessors like .r or .g. (deprecated_member_use)

This warning is for the following code snippet:

String get colorHexString => color.value.toRadixString(16).substring(2);

Warning:

info: 'green' is deprecated and shouldn't be used. Use .g. (deprecated_member_use)

This warning is for this part of the code:

String toHex({bool hashSign = false, bool withAlpha = false}) =>
  '${hashSign ? '#' : ''}'
          '${_generateAlpha(alpha: alpha, withAlpha: withAlpha)}'
          '${red.toRadixString(16).padLeft(2, '0')}'
          '${green.toRadixString(16).padLeft(2, '0')}'
          '${blue.toRadixString(16).padLeft(2, '0')}'
      .toUpperCase();
Tags:

2

Answers


  1. Chosen as BEST ANSWER
    0

    The following solutions worked for me:

    1. colorHexString Getter:

    This method constructs the hex string for a Color object, including its alpha value:

     String get colorHexString {
    final red = (color.r * 255).toInt().toRadixString(16).padLeft(2, '0');
    final green = (color.g * 255).toInt().toRadixString(16).padLeft(2, '0');
    final blue = (color.b * 255).toInt().toRadixString(16).padLeft(2, '0');
    final alpha = (color.a * 255).toInt().toRadixString(16).padLeft(2, '0');

    return '$alpha$red$green$blue';
  }
    1. toHex Method:

    This method generates a hex string for a Color object with optional parameters for including a hash sign (#) and alpha transparency:

       String toHex({bool hashSign = false, bool withAlpha = false}) {
    final alpha = (a * 255).toInt().toRadixString(16).padLeft(2, '0');
    final red = (r * 255).toInt().toRadixString(16).padLeft(2, '0');
    final green = (g * 255).toInt().toRadixString(16).padLeft(2, '0');
    final blue = (b * 255).toInt().toRadixString(16).padLeft(2, '0');

    return '${hashSign ? '#' : ''}'
            '${withAlpha ? alpha : ''}'
            '$red$green$blue'
        .toUpperCase();
  }

  2. 0

    I created this utils class to convert from Color to int and vice versa

    import 'dart:ui';

class AppColorUtils {
  // Convert Color to int
  static int colorToInt(Color color) {
    // Convert alpha from 0.0-1.0 to 0-255
    final a = (color.a * 255).round();
    // For r,g,b, just round to the nearest integer
    final r = color.r.round();
    final g = color.g.round();
    final b = color.b.round();

    // Combine the components into a single int using bit shifting
    return (a << 24) | (r << 16) | (g << 8) | b;
  }

// Convert int to Color
  static Color intToColor(int value) {
    // Extract alpha and convert to 0.0-1.0
    final a = ((value >> 24) & 0xFF) / 255.0;
    // Extract r,g,b as direct double values
    final r = ((value >> 16) & 0xFF);
    final g = ((value >> 8) & 0xFF);
    final b = (value & 0xFF);

    return Color.fromRGBO(r.round(), g.round(), b.round(), a);
  }
}

    In your case you would only have to do:

    String get colorHexString => AppColorUtils.colorToInt(color.value).toRadixString(16).substring(2);
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