setCookie: function (cname, cvalue, exdays) {
  let d = new Date()
  d.setTime(d.getTime() + (exdays * 24 * 60 * 60 * 1000))
  let expires = 'expires=' + d.toUTCString()
  document.cookie = cname + '=' + cvalue + '; ' + expires
},
getCookie: function (cname) {
  let name = cname + '='
  let ca = document.cookie.split(';')
  // console.log("获取cookie,现在循环")
  for (let i = 0; i < ca.length; i++) {
    let c = ca[i]
    // console.log(c)
    while (c.charAt(0) === ' ') c = c.substring(1)
    if (c.indexOf(name) !== -1) {
      return c.substring(name.length, c.length)
    }
  }
  return ''
},
clearCookie: function (cname) {
  this.setCookie(cname, '', -1)
}