CODEWITHSUNDEEP
stringcolorsdartflutter
Jus10
Jus10

Reputation: 15699

Flutter/Dart: Convert HEX color string to Color?

Our database has colors saved as a String like "#AABBCC" and so I'm basically looking for a function like this: Color.parseColor("#AABBCC"); for Flutter

The Color class requires something like this Color(0xFF42A5F5) so I need to convert "#AABBCC" to 0xFFAABBCC

Upvotes: 36

Views: 54118

Answers (6)

crookshanksacademy.com
crookshanksacademy.com

Reputation: 574

This can be done using a function-

toColor(String hex) {
    var hexColor = hex.replaceAll("#", "");
    if (hexColor.length == 6) {
      hexColor = "FF" + hexColor;
    }
    if (hexColor.length == 8) {
      return Color(int.parse("0x$hexColor"));
    }
  }

You can pass your string in this function and it will return the color to you,

Upvotes: 1

hasanm08
hasanm08

Reputation: 638

first define this extention

extension HexToColor on String {
  Color hexToColor() {
    return Color(
        int.parse(toLowerCase().substring(1, 7), radix: 16) + 0xFF000000);
  }
}

then use it where needed

Color color = hexStr.hexToColor()

Upvotes: 2

Mertcan Diken
Mertcan Diken

Reputation: 15361

I'm using this function in my project which handles converting the hex string to a Color.

Color hexToColor(String hexString, {String alphaChannel = 'FF'}) {
  return Color(int.parse(hexString.replaceFirst('#', '0x$alphaChannel')));
}

The idea here is that now you can pass this function a hex string which is something like this '#ffffff' in addition to that you can pass an alpha channel. What alpha channel does is it handles the opacity of your color and you can pass it to Color directly.

About alpha channels the FF part is a hex representation of 0-100 is like:

0 = 00 1 = 03 2 = 05 ... 9 = 17 ... 10 = 1A 11 = 1C 12 = 1F ... 99 = FC 100 = FF

Let's assume you want to convert #000000 into a Color and have a 0.1 opacity on it. You can simply call this function like this: 

hexToColor('#000000', alphaChannel: '1A');

And if you just call it like this:

hexToColor('#000000');

Then it will only return you a black color with 1 opacity. Hope this will help to anyone wondering how to handle opacity and color handling a bit more further.

Upvotes: 16

Jus10
Jus10

Reputation: 15699

I ended up doing it this way:

hexStringToHexInt(String hex) {
  hex = hex.replaceFirst('#', '');
  hex = hex.length == 6 ? 'ff' + hex : hex;
  int val = int.parse(hex, radix: 16);
  return val;
}

Upvotes: 5

Richard Heap
Richard Heap

Reputation: 51751

/// Construct a color from a hex code string, of the format #RRGGBB.
Color hexToColor(String code) {
  return new Color(int.parse(code.substring(1, 7), radix: 16) + 0xFF000000);
}

Upvotes: 86

Kingsley
Kingsley

Reputation: 14926

A simple string replacement would get it in the right syntax:

String html_colour = '#AAABBCC';
String fixed_colour = html_colour.replace(new RegExp(r'#'), '0xFF');

That should do it.

Upvotes: 4

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