如何将颜色在RGB格式转换为十六进制格式,反之亦然?
例如,将'#0080C0'转换为(0,128,192)。
如何将颜色在RGB格式转换为十六进制格式,反之亦然?
例如,将'#0080C0'转换为(0,128,192)。
当前回答
接受字符串的简写版本:
function rgbToHex(a){ a=a.replace(/[^\d,]/g,“”).split(“,”); return“#”+((1<<24)+(+a[0]<<16)+(+a[1]<<8)+ +a[2]).toString(16).slice(1) } document.write(rgbToHex(“rgb(255,255,255)”));
来检查它是否已经是十六进制
function rgbToHex(a){ if(~a.indexOf(“#”))返回 a; a=a.replace(/[^\d,]/g,“”).split(“,”); return“#”+((1<<24)+(+a[0]<<16)+(+a[1]<<8)+ +a[2]).toString(16).slice(1) } document.write(“rgb: ”+rgbToHex(“rgb(255,255,255)”)+ “ -- hex: ”+rgbToHex(“#e2e2e2”));
其他回答
建立了我自己的十六进制RGB转换器。我希望这能帮助到一些人。
我用react来做沙盒。
用法:
根据官方文档安装React,或者如果你全局安装了npx,运行npx create-react-app hexto -rgb
import React, { Component, Fragment } from 'react';
const styles = {
display: 'block',
margin: '20px auto',
input: {
width: 170,
},
button: {
margin: '0 auto'
}
}
// test case 1
// #f0f
// test case 2
// #ff00ff
class HexToRGBColorConverter extends Component {
state = {
result: false,
color: "#ff00ff",
}
hexToRgb = color => {
let container = [[], [], []];
// check for shorthand hax string
if (color.length >= 3) {
// remove hash from string
// convert string to array
color = color.substring(1).split("");
for (let key = 0; key < color.length; key++) {
let value = color[key];
container[2].push(value);
// if the length is 3 we
// we need to add the value
// to the index we just updated
if (color.length === 3) container[2][key] += value;
}
for (let index = 0; index < color.length; index++) {
let isEven = index % 2 === 0;
// If index is odd an number
// push the value into the first
// index in our container
if (isEven) container[0].push(color[index]);
// If index is even an number
if (!isEven) {
// again, push the value into the
// first index in the container
container[0] += color[index];
// Push the containers first index
// into the second index of the container
container[1].push(container[0]);
// Flush the first index of
// of the container
// before starting a new set
container[0] = [];
}
}
// Check container length
if (container.length === 3) {
// Remove only one element of the array
// Starting at the array's first index
container.splice(0, 1);
let values = container[color.length % 2];
return {
r: parseInt(values[0], 16),
g: parseInt(values[1], 16),
b: parseInt(values[2], 16)
}
}
}
return false;
}
handleOnClick = event => {
event.preventDefault();
const { color } = this.state;
const state = Object.assign({}, this.state);
state.result = this.hexToRgb(color);
this.setState(state);
}
handleOnChange = event => {
event.preventDefault();
const { value } = event.currentTarget;
const pattern = /^([a-zA-Z0-9])/;
const boundaries = [3, 6];
if (
pattern.test(value) &&
boundaries.includes(value.length)
) {
const state = Object.assign({}, this.state);
state.color = `#${value}`;
this.setState(state);
}
}
render() {
const { color, result } = this.state;
console.log('this.state ', color, result);
return (
<Fragment>
<input
type="text"
onChange={this.handleOnChange}
style={{ ...styles, ...styles.input }} />
<button
onClick={this.handleOnClick}
style={{ ...styles, ...styles.button }}>
Convert hex to rgba
</button>
{
!!result &&
<div style={{ textAlign: 'center' }}>
Converted { color } to { JSON.stringify(result) }
</div>
}
</Fragment>
)
}
}
export default App;
快乐编码=)
hexToRgb的另一个版本:
function hexToRgb(hex) {
var bigint = parseInt(hex, 16);
var r = (bigint >> 16) & 255;
var g = (bigint >> 8) & 255;
var b = bigint & 255;
return r + "," + g + "," + b;
}
编辑:3/28/2017 这是另一种似乎更快的方法
function hexToRgbNew(hex) {
var arrBuff = new ArrayBuffer(4);
var vw = new DataView(arrBuff);
vw.setUint32(0,parseInt(hex, 16),false);
var arrByte = new Uint8Array(arrBuff);
return arrByte[1] + "," + arrByte[2] + "," + arrByte[3];
}
编辑:8/11/2017 经过更多测试后,上面的新方法并没有更快:(。虽然这是一种有趣的替代方式。
以下是我的看法:
function rgbToHex(red, green, blue) {
const rgb = (red << 16) | (green << 8) | (blue << 0);
return '#' + (0x1000000 + rgb).toString(16).slice(1);
}
function hexToRgb(hex) {
const normal = hex.match(/^#([0-9a-f]{2})([0-9a-f]{2})([0-9a-f]{2})$/i);
if (normal) return normal.slice(1).map(e => parseInt(e, 16));
const shorthand = hex.match(/^#([0-9a-f])([0-9a-f])([0-9a-f])$/i);
if (shorthand) return shorthand.slice(1).map(e => 0x11 * parseInt(e, 16));
return null;
}
这段代码接受#fff和#ffffff变量和不透明度。
function hex2rgb(hex, opacity) {
var h=hex.replace('#', '');
h = h.match(new RegExp('(.{'+h.length/3+'})', 'g'));
for(var i=0; i<h.length; i++)
h[i] = parseInt(h[i].length==1? h[i]+h[i]:h[i], 16);
if (typeof opacity != 'undefined') h.push(opacity);
return 'rgba('+h.join(',')+')';
}
我建议使用一个经过良好测试和维护的库:Colors.js(可用于node.js和浏览器),而不是复制和粘贴到处都能找到的代码片段。它只有7 KB(压缩后更少)。