CSS 数字工厂函数

Baseline Widely available *

This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2015.

* Some parts of this feature may have varying levels of support.

CSS 数字工厂函数（例如 CSS.em() 和 CSS.turn()）是返回 CSSUnitValue 的方法，其中值为实际参数，单位是所使用的方法名称。这些函数创建新的数值比使用 CSSUnitValue() 构造函数更加简洁。

语法

CSS.number(number)
CSS.percent(number)

// <length>
CSS.em(number)
CSS.ex(number)
CSS.ch(number)
CSS.ic(number)
CSS.rem(number)
CSS.lh(number)
CSS.rlh(number)
CSS.vw(number)
CSS.vh(number)
CSS.vi(number)
CSS.vb(number)
CSS.vmin(number)
CSS.vmax(number)
CSS.cm(number)
CSS.mm(number)
CSS.Q(number)
CSS.in(number)
CSS.pt(number)
CSS.pc(number)
CSS.px(number)

// <angle>
CSS.deg(number)
CSS.grad(number)
CSS.rad(number)
CSS.turn(number)

// <time>
CSS.s(number)
CSS.ms(number)

// <frequency>
CSS.Hz(number)
CSS.kHz(number)

// <resolution>
CSS.dpi(number)
CSS.dpcm(number)
CSS.dppx(number)

// <flex>
CSS.fr(number)

示例

我们使用 CSS.vmax() 数字工厂函数来创建 CSSUnitValue：

const height = CSS.vmax(50);

console.log(height); // CSSUnitValue {value: 50, unit: "vmax"}
console.log(height.value); // 50
console.log(height.unit); // vmax

在此示例中，我们使用 CSS.px() 工厂函数给元素设置外边距：

myElement.attributeStyleMap.set("margin", CSS.px(40));
const currentMargin = myElement.attributeStyleMap.get("margin");
console.log(currentMargin.value, currentMargin.unit); // 40, 'px'

规范

Specification
CSS Object Model (CSSOM) # namespacedef-css

浏览器兼容性

参见

CSSUnitValue()