Swift Can';无法从firebase获取值
当我试图从数据库中获取isBusy属性的值时出现问题。一个已使用的断点,它甚至不进入指令,在指令中我为isBusy赋值,它分配空字符串并进入else条件Swift Can';无法从firebase获取值,swift,firebase,firebase-realtime-database,Swift,Firebase,Firebase Realtime Database,当我试图从数据库中获取isBusy属性的值时出现问题。一个已使用的断点,它甚至不进入指令,在指令中我为isBusy赋值,它分配空字符串并进入else条件 if docChild == 0 { let selectedDoctor = Doctors.doc1 var isBusy = String() databaseHandle = reference.child(selectedDoctor).child(dateChild).child(t
if docChild == 0 {
let selectedDoctor = Doctors.doc1
var isBusy = String()
databaseHandle = reference.child(selectedDoctor).child(dateChild).child(timeChild).child(ReservationFields.isBusy).observe(.childAdded, with: { (snapshot) in
isBusy = snapshot.value as! String
})
if isBusy == "false" {
reference.child(selectedDoctor).child(dateChild).child(timeChild).child(ReservationFields.isBusy).setValue("true")
reference.child(selectedDoctor).child(dateChild).child(timeChild).child(ReservationFields.firstname).setValue(firstNameLabel.text)
reference.child(selectedDoctor).child(dateChild).child(timeChild).child(ReservationFields.lastname).setValue(lastNameLabel.text)
reference.child(selectedDoctor).child(dateChild).child(timeChild).child(ReservationFields.pesel).setValue(peselLabel.text)
reference.child(selectedDoctor).child(dateChild).child(timeChild).child(ReservationFields.telephone).setValue(phoneLabel.text)
} else {
createAlert(title: "Przepraszamy - termin jest zajęty", message: "Proszę wybrać inny termin")
}
答案相当简单。Firebase数据库请求是异步的,因此当您到达
if isBusy==“false”
语句时,该值没有从数据库中获取。相应地更改代码:
if docChild == 0 {
let selectedDoctor = Doctors.doc1
var isBusy = String()
databaseHandle = reference.child(selectedDoctor).child(dateChild).child(timeChild).child(ReservationFields.isBusy).observe(.childAdded, with: { (snapshot) in
isBusy = snapshot.value as! String
if isBusy == "false" {
reference.child(selectedDoctor).child(dateChild).child(timeChild).child(ReservationFields.isBusy).setValue("true")
reference.child(selectedDoctor).child(dateChild).child(timeChild).child(ReservationFields.firstname).setValue(firstNameLabel.text)
reference.child(selectedDoctor).child(dateChild).child(timeChild).child(ReservationFields.lastname).setValue(lastNameLabel.text)
reference.child(selectedDoctor).child(dateChild).child(timeChild).child(ReservationFields.pesel).setValue(peselLabel.text)
reference.child(selectedDoctor).child(dateChild).child(timeChild).child(ReservationFields.telephone).setValue(phoneLabel.text)
} else {
createAlert(title: "Przepraszamy - termin jest zajęty", message: "Proszę wybrać inny termin")
}
})
正如您所见,我只是将您的代码移动到了处理程序中,因此在获取了您的值之后,它就会执行。XCode让我写self。在许多地方,现在它不去指令,我给isBusy和next指令赋值。