werun-wxapp/common-page/utils/color.js

const 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]{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] };
        } else {
            result = '无效';
            return { rgb: result };
        }

    }
};

module.exports = colorChange