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如何固定列宽下数字过长时：先继承父级字号，再按设计稿字号逐步 -1 缩小，最小 12；仍超出才 `...`。 适配约定（375 设计稿）： - `html.fontSize = (width / 375) * 100` - postcss `rootValue: 100` → 设计稿 px 转 rem：`px / 100` --- ## 封装：AutoFitText ```tsx import { useLayoutEffect, useRef, type ReactNode } from 'react' /** * 与 index.html / postcss-pxtorem 一致： * - 设计稿 375 * - html fontSize = (width / 375) * 100 * - 设计稿 px → rem：px / 100 */ const DESIGN_ROOT_VALUE = 100 const MIN_DESIGN_FONT_SIZE = 12 interface AutoFitTextProps { children: ReactNode className?: string } const designPxToRem = (designPx: number) => `${designPx / DESIGN_ROOT_VALUE}rem` /** 数字列可用宽度 = 父容器宽 - 兄弟节点宽 - 自身 margin（不改动外部 flex 布局） */ const resolveConstraintWidth = (el: HTMLElement): number => { const parent = el.parentElement if (!parent) return 0 const host = parent.parentElement if (host && host.clientWidth > 0) { let siblingsWidth = 0 const children = host.children for (let i = 0; i < children.length; i += 1) { const child = children[i] as HTMLElement if (child === parent) continue siblingsWidth += child.offsetWidth } const parentStyle = window.getComputedStyle(parent) const margin = (parseFloat(parentStyle.marginLeft) || 0) + (parseFloat(parentStyle.marginRight) || 0) const next = host.clientWidth - siblingsWidth - margin if (next > 0) return next } return parent.clientWidth > 0 ? parent.clientWidth : el.clientWidth } /** * 默认继承父级字号；超出后按设计稿字号逐步 -1 缩小， * 最小 12；仍超出再省略号。 */ export const AutoFitText = ({ children, className }: AutoFitTextProps) => { const ref = useRef<HTMLSpanElement>(null) useLayoutEffect(() => { const el = ref.current if (!el) return const parent = el.parentElement let cancelled = false let rafId = 0 const fit = () => { if (cancelled) return el.style.fontSize = '' el.style.maxWidth = '' el.classList.remove('is-ellipsis') const constraint = resolveConstraintWidth(el) if (constraint <= 0) return // 仅约束自身测量，不改父级 flex，避免把「股」等兄弟顶飞 el.style.maxWidth = `${constraint}px` if (el.scrollWidth <= constraint + 1) { el.style.maxWidth = '' return } const rootPx = parseFloat( window.getComputedStyle(document.documentElement).fontSize, ) || DESIGN_ROOT_VALUE const inheritedCssPx = parseFloat(window.getComputedStyle(el).fontSize) || 14 let designSize = Math.round((inheritedCssPx / rootPx) * DESIGN_ROOT_VALUE) while ( designSize > MIN_DESIGN_FONT_SIZE && el.scrollWidth > constraint + 1 ) { designSize -= 1 el.style.fontSize = designPxToRem(designSize) } if (el.scrollWidth > constraint + 1) { el.classList.add('is-ellipsis') } else { // 缩到能放下后去掉 maxWidth，避免多余裁切 el.style.maxWidth = '' } } const scheduleFit = () => { if (rafId) window.cancelAnimationFrame(rafId) rafId = window.requestAnimationFrame(fit) } fit() scheduleFit() window.addEventListener('resize', scheduleFit, false) let resizeObserver: ResizeObserver | null = null if (typeof ResizeObserver !== 'undefined') { resizeObserver = new ResizeObserver(scheduleFit) if (parent) resizeObserver.observe(parent) if (parent?.parentElement) resizeObserver.observe(parent.parentElement) } const fonts = document.fonts if (fonts?.ready) { void fonts.ready.then(() => { if (!cancelled) scheduleFit() }) } return () => { cancelled = true if (rafId) window.cancelAnimationFrame(rafId) window.removeEventListener('resize', scheduleFit, false) resizeObserver?.disconnect() } }, [children]) return ( <span ref={ref} className={`trade-order-bottom__auto-fit-text${ className ? ` ${className}` : '' }`} > {children} </span> ) } ``` 配套样式： ```less &__auto-fit-text { display: block; width: 100%; min-width: 0; overflow: hidden; font-size: inherit; line-height: inherit; color: inherit; font-family: inherit; white-space: nowrap; text-overflow: clip; &.is-ellipsis { text-overflow: ellipsis; } } /* 容器必须有固定宽度，文字节点占满宽度，才能正确测溢出 */ .demo-box { width: 120px; overflow: hidden; font-size: 16px; > span { display: block; width: 100%; max-width: 100%; overflow: hidden; white-space: nowrap; } } ``` --- ## 使用案例（独立 Demo） ```tsx import { useState } from 'react' import { AutoFitText } from './auto-fit-text' export default function AutoFitTextDemo() { const [text, setText] = useState('12345678901234567890') return ( <div> <input value={text} onChange={(e) => setText(e.target.value)} placeholder="输入一段文字试试" /> {/* 固定 120px 宽，观察字号缩小 / 省略号 */} <div className="demo-box"> <AutoFitText>{text}</AutoFitText> </div> </div> ) } ``` 效果说明： 1. 输入较短内容：保持父级 `16px` 2. 内容变长：字号逐步降到 `15 → 14 → … → 12` 3. 到 `12` 仍放不下：显示 `...` --- ## 注意点 1. 父容器要有明确宽度，且 `overflow: hidden` 2. 文字节点 `width: 100%` + `white-space: nowrap`，否则 `scrollWidth === clientWidth` 测不准 3. 缩小后写 rem（`设计稿px / 100`），不要写死 `px` 4. 未缩小时清空内联 `fontSize`，继续继承父级字号 |
