Js 实现十六进制颜色值和RGB颜色值转换整理

var colorChange = {

rgbToHex: function (val) { //RGB(A)颜色转换为HEX十六进制的颜色值

var r, g, b, a,

regRgba = /rgba?((\d{1,3}),(\d{1,3}),(\d{1,3})(,([.\d]+))?)/, //判断rgb颜色值格式的正则表达式，如rgba(255,20,10,.54)

rsa = val.replace(/\s+/g, ‘’).match(regRgba);

if (!!rsa) {

r = parseInt(rsa[1]).toString(16);

r = r.length == 1 ? ‘0’ + r : r;

g = (+rsa[2]).toString(16);

g = g.length == 1 ? ‘0’ + g : g;

b = (+rsa[3]).toString(16);

b = b.length == 1 ? ‘0’ + b : b;

a = (+(rsa[5] ? rsa[5] : 1)) * 100;

return { hex: ‘#’ + r + g + b, r: parseInt(r, 16), g: parseInt(g, 16), b: parseInt(b, 16), alpha: Math.ceil(a) };

} else {

return { hex: ‘无效’, alpha: 100 };

}

},

hexToRgb: function (val) { //HEX十六进制颜色值转换为RGB(A)颜色值

// 16进制颜色值的正则

var reg = /^#([0-9a-fA-f]{3}|[0-9a-fA-f] 《大厂前端面试题解析+Web核心总结学习笔记+企业项目实战源码+最新高清讲解视频》无偿开源 徽信搜索公众号【编程进阶路】 {6})$/;

// 把颜色值变成小写

var color = val.toLowerCase();

var result = ‘’;

if (reg.test(color)) {

// 如果只有三位的值，需变成六位，如：#fff => #ffffff

if (color.length === 4) {

var colorNew = “#”;

for (var i = 1; i < 4; i += 1) {

colorNew += color.slice(i, i + 1).concat(color.slice(i, i + 1));

}

color = colorNew;

}

// 处理六位的颜色值，转为RGB

var colorChange = [];

for (var i = 1; i < 7; i += 2) {

colorChange.push(parseInt(“0x” + color.slice(i, i + 2)));

}

result = “rgb(” + colorChange.join(“,”) + “)”;

return { rgb: result, r: colorChange[0], g: colorChange[1], b: colorChange[2] };