operation is not allowed on an object referencing a closed or invalid connection
用同一段代码给一个adoquery和一个adoconnecton的connectionstring赋值(从配置文件中读取并组合),一个放在adoquery的连接放在login窗口的create事件里,adoconnection的连接放在main窗口的create时间里,登陆窗口的登陆按钮调用main的create()方法,但是adoquery连接没问题,只有adoconnection始终连不上,提示“operation is not allowed on an object referencing a closed or invalid connection”错误,不知道怎么回事