window.localStorage.setItem('UserC', JSON.stringify(userC))

const userC = JSON.parse(window.localStorage.getItem('UserC') || '{}')

不能获得UserC，所有保存的时候需要存储value，而不是对象。

{"__v_isShallow":false,

"__v_isRef":true,

"_rawValue":{"userId":1,"userName":"name","userFullName":"abc","roleId":abc,"roleName":"ABC"},

"_value":{"userId":1,"userName":"name","userFullName":"abc","roleId":abc,"roleName":"ABC"}}

window.localStorage.setItem('UserCache', JSON.stringify(userCache.value))

{
  "userId": 1,
  "userName": "name",
  "roleId": abc,
  "roleName": "ABC"
}