更改状态属性值会更新 UI，但应用程序崩溃但 XCode 中没有任何错误报告 | 用户界面

Question

I am using the below code for otp verification. When the state property canSignUp is updated then the verified mobileNumber gets printed in the Text in the else block but as soon as it happens the app crashes and the xcode debugger doesn't show anything related to the crash.

           @State var mobileNumber = ""
           @State var canSignUp = false


           if !canSignUp {
               OTPView(onVerified: { mobile in
                    self.mobileNumber = mobile
                    self.canSignUp = true
                })
            } else {
                Text(mobileNumber)
            }

The same code doesn't produce any crash in the simulator while it does on a physical device. I am using an iPhone 11 Pro Max

This is what xcode looks like when the app crashes on the physical device

Answer 1

I can't figure out why, but the problem is with using if-else to show and hide the views. The crash was fixed when I put the views outside of if-else and used opacity to show and hide them. Furthermore, I put the views inside a ZStack so that the Text field doesn't get pushed down by the OTPView. Here's what it looks like.

                   ZStack(alignment: .top) {
                       OTPView(onVerified: { mobile in
                            self.mobileNumber = mobile
                            self.canSignUp = true
                        }).opacity(!canSignUp ? 1 : 0)
                        
                        Text(mobileNumber).opacity(canSignUp ? 1 : 0)
                    }

While I am happy with this solution. I would still love to know why wouldn't it work if the visibility of the views are controlled with if-else