色觉适配方案：HarmonyOS5色彩对比度校验工具使用指南

以下为 ​​HarmonyOS 5色彩对比度校验工具的完整ArkTS实现方案​​，包含自动检测、动态调整和可视化报告的代码示例：

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1. 色彩校验架构

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2. 核心校验工具

2.1 对比度计算算法

// contrast-calculator.ets
export function calculateContrast(fg: string, bg: string): number {
  const luminance = (color: string) => {
    const rgb = Color.parse(color).toRGB();
    const [r, g, b] = [rgb.r, rgb.g, rgb.b].map(v => {
      v /= 255;
      return v <= 0.03928 ? v / 12.92 : Math.pow((v + 0.055) / 1.055, 2.4);
    });
    return 0.2126 * r + 0.7152 * g + 0.0722 * b;
  };

  const l1 = luminance(fg) + 0.05;
  const l2 = luminance(bg) + 0.05;
  return Math.max(l1, l2) / Math.min(l1, l2);
}

2.2 WCAG标准验证

// wcag-checker.ets
export function checkWCAG(fg: string, bg: string) {
  const ratio = calculateContrast(fg, bg);
  return {
    AA: ratio >= 4.5,
    AAA: ratio >= 7,
    AA_LargeText: ratio >= 3,
    actualRatio: Math.round(ratio * 100) / 100
  };
}

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3. 动态调色方案

3.1 自动色彩修正

// color-adjuster.ets
export function ensureContrast(fg: string, bg: string, level: 'AA' | 'AAA' = 'AA') {
  const targetRatio = level === 'AA' ? 4.5 : 7;
  let current = fg;
  
  while (calculateContrast(current, bg) < targetRatio) {
    current = Color.parse(current)
      .adjustLightness(0.05)
      .saturate(0.1)
      .hex();
  }

  return current;
}

3.2 安全色板生成

// safe-palette.ets
export function generateAccessiblePalette(base: string) {
  return {
    text: ensureContrast('#000000', base),
    secondaryText: ensureContrast('#666666', base),
    divider: ensureContrast('#EEEEEE', base)
  };
}

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4. 可视化校验工具

4.1 实时对比度检测器

// live-checker.ets
@Component
struct ContrastChecker {
  @State fg: string = '#000000';
  @State bg: string = '#FFFFFF';
  @State result: any = {};

  build() {
    Column() {
      ColorPicker({ value: this.fg })
        .onChange(v => this.update('fg', v))
      
      ColorPicker({ value: this.bg })
        .onChange(v => this.update('bg', v))
      
      ContrastResultCard(this.result)
    }
  }

  update(type: string, value: string) {
    this[type] = value;
    this.result = checkWCAG(this.fg, this.bg);
  }
}

4.2 色盲模拟器

// color-blindness.ets
export function simulateColorBlindness(type: 'protanopia' | 'deuteranopia' | 'tritanopia') {
  const matrices = {
    protanopia: [0.567, 0.433, 0, 0.558, 0.442, 0, 0, 0.242, 0.758],
    deuteranopia: [0.625, 0.375, 0, 0.7, 0.3, 0, 0, 0.3, 0.7],
    tritanopia: [0.95, 0.05, 0, 0, 0.433, 0.567, 0, 0.475, 0.525]
  };

  return (color: string) => {
    const rgb = Color.parse(color).toRGB();
    const [r, g, b] = applyMatrix(rgb, matrices[type]);
    return Color.rgb(r, g, b).hex();
  };
}

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5. 完整应用示例

5.1 色彩校验面板

// contrast-panel.ets
@Component
struct ContrastTool {
  @State colorPairs: Array<{fg: string, bg: string}> = [    {fg: '#000000', bg: '#FFFFFF'}  ];

  build() {
    List() {
      ForEach(this.colorPairs, (pair, index) => {
        ListItem() {
          ContrastRow({
            foreground: pair.fg,
            background: pair.bg,
            onFix: (fixed) => this.colorPairs[index].fg = fixed
          })
        }
      })
      
      ListItem() {
        Button('+ 添加对比组')
          .onClick(() => this.addPair())
      }
    }
  }

  addPair() {
    this.colorPairs.push({fg: '#000000', bg: '#FFFFFF'});
  }
}

5.2 自动修复组件

// auto-fixer.ets
@Component
struct ContrastFixer {
  @Prop fg: string;
  @Prop bg: string;
  @State suggested: string = '';

  aboutToAppear() {
    this.suggested = ensureContrast(this.fg, this.bg);
  }

  build() {
    Row() {
      Text('当前对比度: ' + calculateContrast(this.fg, this.bg).toFixed(2))
      Button('应用建议色')
        .onClick(() => this.applyFix())
    }
  }

  applyFix() {
    this.fg = this.suggested;
  }
}

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6. 开发者工具集成

6.1 设计稿校验

// design-validator.ets
export function validateDesign(spec: DesignSpec) {
  return spec.elements.map(element => {
    const ratio = calculateContrast(element.text, element.background);
    return {
      ...element,
      meetsAA: ratio >= 4.5,
      meetsAAA: ratio >= 7,
      ratio
    };
  });
}

6.2 CI/CD集成

# .github/workflows/color-check.yml
name: Color Contrast Check
on: [push]

jobs:
  check:
    runs-on: ubuntu-latest
    steps:
      - uses: harmonyos/color-checker@v1
        with:
          threshold: 'AA'
          paths: 'src/**/*.ets'

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7. 高级功能扩展

7.1 动态主题适配

// dynamic-theme.ets
export function adaptThemeForAccessibility(theme: Theme) {
  return {
    ...theme,
    text: ensureContrast(theme.text, theme.background),
    primary: ensureContrast(theme.primary, theme.background)
  };
}

7.2 批量色板校验

// batch-checker.ets
export function checkPalette(palette: Record<string, string>) {
  const results: Record<string, any> = {};
  const colors = Object.values(palette);
  
  for (let i = 0; i < colors.length; i++) {
    for (let j = i + 1; j < colors.length; j++) {
      const key = `${colors[i]}-${colors[j]}`;
      results[key] = checkWCAG(colors[i], colors[j]);
    }
  }
  
  return results;
}

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8. 关键校验指标

标准	最小对比度	适用场景
WCAG AA	4.5:1	标准文本
WCAG AAA	7:1	高要求场景
WCAG AA Large Text	3:1	18pt+或14pt粗体
WCAG UI Components	3:1	按钮/图标等交互元素

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9. 项目结构规范

color-accessibility/
├── src/
│   ├── core/            # 核心算法
│   ├── tools/           # 校验工具
│   ├── adapters/        # 设计系统适配
│   └── reports/         # 可视化报告
├── assets/
│   ├── palettes/        # 色板配置
│   └── test-cases/      # 测试用例
└── test/
    ├── unit/            # 单元测试
    └── visual/          # 视觉测试

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10. 使用示例

10.1 快速校验

// quick-check.ets
const { AA, actualRatio } = checkWCAG('#FF5722', '#FFFFFF');
console.log(`对比度: ${actualRatio}, ${AA ? '通过' : '不通过'}AA标准`);

10.2 自动修复

// auto-fix-demo.ets
const badColor = '#AAAAAA';
const fixed = ensureContrast(badColor, '#FFFFFF');
console.log(`修正后颜色: ${fixed}`);

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通过本方案可实现：

1. ​​100%​​ WCAG合规检测
2. ​​实时​​ 色彩对比度反馈
3. ​​一键式​​ 自动修正
4. ​​可视化​​ 色盲模拟