打印纸张尺寸

复制from dataclasses import dataclass
from typing import Dict

@dataclass
class PaperSize:
    name: str
    width_mm: float
    height_mm: float

# ISO 216 A 系列标准尺寸（毫米）
A_SERIES: Dict[str, PaperSize] = {
    "A0": PaperSize("A0", 841, 1189),
    "A1": PaperSize("A1", 594, 841),
    "A2": PaperSize("A2", 420, 594),
    "A3": PaperSize("A3", 297, 420),
    "A4": PaperSize("A4", 210, 297),
    "A5": PaperSize("A5", 148, 210),
    "A6": PaperSize("A6", 105, 148),
    "A7": PaperSize("A7", 74, 105),
    "A8": PaperSize("A8", 52, 74),
}

# 按名称查找尺寸，返回 (宽, 高) 毫米
size = A_SERIES["A4"]
print(f"{size.name}: {size.width_mm}×{size.height_mm} mm")
# 输出: A4: 210×297 mm

# 计算对角线（英寸），1 英寸 = 25.4 mm
import math
diag_inch = math.hypot(size.width_mm, size.height_mm) / 25.4
print(f"对角线: {diag_inch:.1f} 英寸")
# 输出: 对角线: 14.3 英寸

复制package main

import (
	"fmt"
	"math"
)

type PaperSize struct {
	Name       string
	WidthMM    float64
	HeightMM   float64
}

// ISO 216 B 系列标准尺寸（毫米）
var BSeries = map[string]PaperSize{
	"B0": {"B0", 1000, 1414},
	"B1": {"B1", 707, 1000},
	"B2": {"B2", 500, 707},
	"B3": {"B3", 353, 500},
	"B4": {"B4", 250, 353},
	"B5": {"B5", 176, 250},
	"B6": {"B6", 125, 176},
	"B7": {"B7", 88, 125},
	"B8": {"B8", 62, 88},
}

func main() {
	size, ok := BSeries["B5"]
	if !ok {
		fmt.Println("未找到该尺寸")
		return
	}
	// 输出尺寸
	fmt.Printf("%s: %.0f×%.0f mm\n", size.Name, size.WidthMM, size.HeightMM)
	// B5: 176×250 mm

	// 计算面积（平方米）
	area := size.WidthMM * size.HeightMM / 1_000_000
	fmt.Printf("面积: %.4f m²\n", area)
	// 面积: 0.0440 m²

	// 计算长宽比（保留 2 位小数）
	ratio := math.Round(size.WidthMM/size.HeightMM*100) / 100
	fmt.Printf("长宽比: %.2f\n", ratio)
	// 长宽比: 0.70
}

复制// 名片标准尺寸（毫米），含出血
const businessCard = {
  name: '标准名片',
  width: 90,
  height: 54,
  bleed: 2, // 出血边距
};

// 信封常见尺寸（毫米）
const envelopes = [
  { name: 'DL', width: 110, height: 220 },
  { name: 'C4', width: 229, height: 324 },
  { name: 'C5', width: 162, height: 229 },
  { name: 'C6', width: 114, height: 162 },
];

// 查找信封并转换单位
function findEnvelope(name) {
  const env = envelopes.find(e => e.name === name.toUpperCase());
  if (!env) throw new Error(`未找到信封: ${name}`);
  
  // 毫米转英寸（1 in = 25.4 mm）
  const toInch = (mm) => (mm / 25.4).toFixed(2);
  
  return {
    ...env,
    widthInch: toInch(env.width),
    heightInch: toInch(env.height),
  };
}

try {
  const c5 = findEnvelope('C5');
  console.log(`${c5.name}: ${c5.width}×${c5.height} mm`);
  // C5: 162×229 mm
  console.log(`英寸: ${c5.widthInch}×${c5.heightInch} in`);
  // 英寸: 6.38×9.02 in
} catch (e) {
  console.error(e.message);
}

// 名片含出血尺寸
const cardWithBleed = {
  width: businessCard.width + businessCard.bleed * 2,
  height: businessCard.height + businessCard.bleed * 2,
};
console.log(`名片（含出血）: ${cardWithBleed.width}×${cardWithBleed.height} mm`);
// 名片（含出血）: 94×58 mm