为什么下面的代码给出了下面的错误？ require 'open3'
module Hosts
def read
include Open3
popen3("cat /etc/hosts") do |i,o,e,w|
puts o.read
end
end
end
Hosts.read
#=> undefined method
我有三个型号，项目转让和类别（又名项目类型）： class Item < ApplicationRecord
belongs_to :category
has_many :transfers
end
class Transfer < ApplicationRecord
belongs_to :item
end
class Category < Applic
使用下面的函数，我遇到了试图访问WriteableBitmap.PixelBuffer属性的问题。我得到的消息是： 'WriteableBitmap' does not contain a definition for 'PixelBuffer' and no extension method 'PixelBuffer' accepting a first argument of type 'Wr