Dart类中的群静态const

Question

我有一个叫做KIcons的图标类。在这个类中，我有两种类型的图标。一个是Solid，另一个是Outlined。现在我想按下面的方式访问它。如何做到这一点？预期输出：KIcons.solid.back_arrow的原因是，当我输入KIcons.solid时，我只应该得到在这个grouping下定义的const列表，因为两者都有相同的和不同的图标。我该如何做到这一点？

目前，我有一个屋檐下的每一件事，并将其命名为solidArrowLeft accessibile，称为KIcons.solidArrowLeft。

代码：

class KIcons {
  // solid
  static const String solidArrowLeft = "assets/icons/solid/arrow-left.svg";
  static const String solidArrowRight = "assets/icons/solid/arrow-right.svg";
  static const String solidArrowTop = "assets/icons/solid/arrow-Top.svg";
  static const String solidArrowBottom = "assets/icons/solid/arrow-bottom.svg";
  static const String solidChevronLeft = "assets/icons/solid/chevron-left.svg";
  static const String solidChevronRight =
      "assets/icons/solid/chevron-right.svg";
  static const String solidChevronTop = "assets/icons/solid/chevron-Top.svg";
  static const String solidChevronBottom =
      "assets/icons/solid/chevron-bottom.svg";
  static const String solidArrowCircleLeft =
      "assets/icons/solid/arrow-circle-left.svg";
  static const String solidArrowCircleRight =
      "assets/icons/solid/arrow-circle-right.svg";
  static const String solidArrowCircleTop =
      "assets/icons/solid/arrow-circle-Top.svg";
  static const String solidArrowCircleBottom =
      "assets/icons/solid/arrow-circle-bottom.svg";

  // outlined
  static const String outlineArrowLeft = "assets/icons/outline/arrow-left.svg";
  static const String outlineArrowRight =
      "assets/icons/outline/arrow-right.svg";
  static const String outlineArrowTop = "assets/icons/outline/arrow-Top.svg";
  static const String outlineArrowBottom =
      "assets/icons/outline/arrow-bottom.svg";
  static const String outlineChevronLeft =
      "assets/icons/outline/chevron-left.svg";
  static const String outlineChevronRight =
      "assets/icons/outline/chevron-right.svg";
  static const String outlineChevronTop =
      "assets/icons/outline/chevron-Top.svg";
  static const String outlineChevronBottom =
      "assets/icons/outline/chevron-bottom.svg";
  static const String outlineArrowCircleLeft =
      "assets/icons/outline/arrow-circle-left.svg";
  static const String outlineArrowCircleRight =
      "assets/icons/outline/arrow-circle-right.svg";
  static const String outlineArrowCircleTop =
      "assets/icons/outline/arrow-circle-Top.svg";
  static const String outlineArrowCircleBottom =
      "assets/icons/outline/arrow-circle-bottom.svg";
}

如能提供帮助，将不胜感激:)

Answer 1

像这样吗？

class KIcons {
  // solid
  static const _KIconsSubType solid = _KIconsSubType('solid');
  
  // outlined
  static const _KIconsSubType outlined = _KIconsSubType('outlined');
}

class _KIconsSubType {
  final String arrowLeft;
  final String arrowRight;
  final String arrowTop;
  final String arrowBottom;
  final String chevronLeft;
  final String chevronRight;
  final String chevronTop;
  final String chevronBottom;
  final String arrowCircleLeft;
  final String arrowCircleRight;
  final String arrowCircleTop;
  final String arrowCircleBottom;

  const _KIconsSubType(String type)
      : arrowLeft = "assets/icons/$type/arrow-left.svg",
        arrowRight = "assets/icons/$type/arrow-right.svg",
        arrowTop = "assets/icons/$type/arrow-Top.svg",
        arrowBottom = "assets/icons/$type/arrow-bottom.svg",
        chevronLeft = "assets/icons/$type/chevron-left.svg",
        chevronRight = "assets/icons/$type/chevron-right.svg",
        chevronTop = "assets/icons/$type/chevron-Top.svg",
        chevronBottom = "assets/icons/$type/chevron-bottom.svg",
        arrowCircleLeft = "assets/icons/$type/arrow-circle-left.svg",
        arrowCircleRight = "assets/icons/$type/arrow-circle-right.svg",
        arrowCircleTop = "assets/icons/$type/arrow-circle-Top.svg",
        arrowCircleBottom = "assets/icons/$type/arrow-circle-bottom.svg";
}

示例，如果您在类型之间有一些差异：

class KIcons {
  // solid
  static const _KIconsSolid solid = _KIconsSolid();

  // outlined
  static const _KIconsOutlined outlined = _KIconsOutlined();
}

class _KIconsSubTypeCommon {
  final String arrowLeft;
  final String arrowRight;
  final String arrowTop;
  final String arrowBottom;
  final String chevronLeft;
  final String chevronRight;
  // final String chevronTop;
  final String chevronBottom;
  final String arrowCircleLeft;
  final String arrowCircleRight;
  final String arrowCircleTop;
  final String arrowCircleBottom;

  const _KIconsSubTypeCommon(String type)
      : arrowLeft = "assets/icons/$type/arrow-left.svg",
        arrowRight = "assets/icons/$type/arrow-right.svg",
        arrowTop = "assets/icons/$type/arrow-Top.svg",
        arrowBottom = "assets/icons/$type/arrow-bottom.svg",
        chevronLeft = "assets/icons/$type/chevron-left.svg",
        chevronRight = "assets/icons/$type/chevron-right.svg",
        // chevronTop = "assets/icons/solid/chevron-Top.svg",
        chevronBottom = "assets/icons/$type/chevron-bottom.svg",
        arrowCircleLeft = "assets/icons/$type/arrow-circle-left.svg",
        arrowCircleRight = "assets/icons/$type/arrow-circle-right.svg",
        arrowCircleTop = "assets/icons/$type/arrow-circle-Top.svg",
        arrowCircleBottom = "assets/icons/$type/arrow-circle-bottom.svg";
}

class _KIconsSolid extends _KIconsSubTypeCommon {
  final String chevronTop;

  const _KIconsSolid()
      : chevronTop = "assets/icons/solid/chevron-Top.svg",
        super("solid");
}

class _KIconsOutlined extends _KIconsSubTypeCommon {
  const _KIconsOutlined() : super("outlined");
}