16进制转rgba

/**
 * 16进制转rgba
 * 主要用于视觉图上给的有16进制颜色和opacity时，会于视觉稿有差异，现在通过这个方法直接转换成rgba
 * @param {不透明度} opacity
 */
/* eslint-disable-next-line */
String.prototype.colorRgba = function(opacity = 1) {
  // 16进制颜色值的正则
  const reg = /^#([0-9a-fA-f]{3}|[0-9a-fA-f]{6})$/
  // 把颜色值变成小写
  let color = this.toLowerCase()
  if (reg.test(color)) {
    // 如果只有三位的值，需变成六位，如：#fff => #ffffff
    if (color.length === 4) {
      let colorNew = "#"
      for (let i = 1; i < 4; i += 1) {
        colorNew += color.slice(i, i + 1).concat(color.slice(i, i + 1))
      }
      color = colorNew
    }
    // 处理六位的颜色值，转为RGB
    const colorChange = []
    for (let i = 1; i < 7; i += 2) {
      colorChange.push(parseInt(`0x${color.slice(i, i + 2)}`, 16))
    }
    return `rgba(${colorChange.join(",")},${opacity})`
  }
  return color
}