如果你想使用不透明度的颤振十六进制颜色

只使用。Color(0x800F1D41)表示50%，80表示50%。

详情请点击这里

在文件中添加此函数

Color parseColor(String color) {
  String hex = color.replaceAll("#", "");
  if (hex.isEmpty) hex = "ffffff";
  if (hex.length == 3) {
    hex = '${hex.substring(0, 1)}${hex.substring(0, 1)}${hex.substring(1, 2)}${hex.substring(1, 2)}${hex.substring(2, 3)}${hex.substring(2, 3)}';
  }
  Color col = Color(int.parse(hex, radix: 16)).withOpacity(1.0);
  return col;
}

然后像-一样使用它

Container(
    color: parseColor("#b74093")
)

要将十六进制字符串转换为整数，请执行以下操作:

int hexToInt(String hex)
{
  int val = 0;
  int len = hex.length;
  for (int i = 0; i < len; i++) {
    int hexDigit = hex.codeUnitAt(i);
    if (hexDigit >= 48 && hexDigit <= 57) {
      val += (hexDigit - 48) * (1 << (4 * (len - 1 - i)));
    } else if (hexDigit >= 65 && hexDigit <= 70) {
      // A..F
      val += (hexDigit - 55) * (1 << (4 * (len - 1 - i)));
    } else if (hexDigit >= 97 && hexDigit <= 102) {
      // a..f
      val += (hexDigit - 87) * (1 << (4 * (len - 1 - i)));
    } else {
      throw new FormatException("Invalid hexadecimal value");
    }
  }
  return val;
}

电话的例子:

Color color = new Color(hexToInt("FFB74093"));

在Flutter中，要从带alpha的RGB创建颜色，请使用:

return new Container(
  color: new Color.fromRGBO(0, 0, 0, 0.5),
);

如何使用十六进制颜色:

return new Container(
  color: new Color(0xFF4286f4),
);
// 0xFF -> the opacity (FF for opaque)
// 4286f4 -> the hexadecimal color

不透明的十六进制颜色:

return new Container(
  color: new Color(0xFF4286f4).withOpacity(0.5),
);

//或改变“FF”值

100% — FF
 95% — F2
 90% — E6
 85% — D9
 80% — CC
 75% — BF
 70% — B3
 65% — A6
 60% — 99
 55% — 8C
 50% — 80
 45% — 73
 40% — 66
 35% — 59
 30% — 4D
 25% — 40
 20% — 33
 15% — 26
 10% — 1A
 5% — 0D
 0% — 00

要了解更多信息，请参阅官方文档页，Color类- dart:ui库- dart API。

在fromRGB构造函数中使用十六进制数:

Color.fromRGBO(0xb7, 0x40, 0x93, 1),

你可以写一个小的控制台工具来转换字符串:

import 'dart:convert';
import 'dart:io';

void main() {
  while (true) {
    var line = stdin.readLineSync(encoding: utf8);

    print(HexColor.fromHex(line!));
  }
}

class HexColor {
  static fromHex(String hexString) {
    final buffer = StringBuffer();
    if (hexString.length == 6 || hexString.length == 7) buffer.write('ff');
    buffer.write(hexString.replaceFirst('#', ''));
    return int.parse(buffer.toString(), radix: 16);
  }
}