在 swift 中为 uiTextField 添加前缀

Question

I am trying to add country code as prefix to textField so the user can enter the rest of his phone number

   @IBAction func phoneLogin(_ sender: Any) {
    let countryCode = "+1"
    
    guard let phoneNumber = countryCode + MobileLbl.text! else { return }
    
    if ((MobileLbl.text?.isEmpty) != nil) {
        print("Fill Your Number")
    }else {
        OTPtxt.isHidden = false
        VerifyBtn.isHidden = false
    PhoneAuthProvider.provider().verifyPhoneNumber(phoneNumber, uiDelegate: nil) { (verificationId, error) in
        if error == nil {
            guard let verifyId = verificationId else { return }
            self.def.setValue(verifyId, forKey: "verificationId")
            self.def.synchronize()
            
            print(verificationId)
        } else {
            print("Unable to get Secret verification from firebase", error?.localizedDescription)
        }
    }
    
    }
    
}

I got this error Initializer for conditional binding must have Optional type, not 'String'

Answer 1

You're force unwrapping MobileLbl.text! which no longer makes it optional. Take off the exclamation point so it's just MobileLbl.text . Also have to move countryCode to another line as it isn't optional either.

let countryCode = "+1"

guard let phone = MobileLbl.text else { return nil }

let phoneNumber = countryCode + phone