web-utils-super/colorToRGB.js

前端函数库

/**
 * @desc: 16进制颜色转 RGB | RGBA 字符串,有透明度则转换为RGBA
 * @param {String} color 16进制颜色
 * @param {Number} opa 透明度
 * @return {String}
 */
function colorToRGB(color, opa) {
  var pattern = /^(#?)[a-fA-F0-9]{6}$/; //16进制颜色值校验规则
  var isOpa = typeof opa == "number"; //判断是否有设置不透明度
  if (!pattern.test(color)) {
    //如果16进制值不符合规则返回空字符
    return "";
  }
  var v = color.replace(/#/, ""); //如果有#号先去除#号
  var rgbArr = [];
  var rgbStr = "";
  for (var i = 0; i < 3; i++) {
    var item = v.substring(i * 2, i * 2 + 2);
    var num = parseInt(item, 16);
    rgbArr.push(num);
  }
  rgbStr = rgbArr.join();
  rgbStr =
    "rgb" + (isOpa ? "a" : "") + "(" + rgbStr + (isOpa ? "," + opa : "") + ")";
  return rgbStr;
}

module.exports = colorToRGB;