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Why unwind method doesn't work now in UIKit?
Hello everyone, I'm facing a problem that I can't connect the button to the unwind segue. I have made a simple application with three controllers. The unwind segue code is located in Table View Controller. @IBAction func unwindToTableViewController(_ unwindSegue: UIStoryboardSegue) { let sourceViewController = unwindSegue.source } A first segue has been implemented from the Add button on Table View Controller to the View controller. It is a Push type. There is a Save button as Bar Button Item in the View Controller. When I try to drag a connection from Save button to the Exit icon of the View Controller, the context menu does not open indicating the unwind segue. Instead, a context menu appears with different types of segues. At the same time, if I just click the Exit icon, a context menu appears where the unwind method is visible. Just in case, I re-read the documentation again and looked at examples of using the unwind method. There is no mention of this problem anywhere. The only hypothesis left is that this problem is related to the new version of Xcode. The example of application given here was created in XCode 15.3. I have tested the same application on another computer, where the version of Xcode is 13.4.1. There, when I try to drag a connection from the Save button to the Exit icon, a context menu appears with the name of the unwind method. But the problem didn't end there because after the connection is established, the button does not work and the View Controller does not dismiss. I can't understand why this is happens. It worked before. Is that one a bug or the feature? How to fix it? Any ideas would be greatly appreciated!
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690
Mar ’24
How to pass data through Tab Bar Controller? UIKit
Hi everyone, An application has a Tab Bar Controller, two navigation stacks with navigation controllers, and two view controllers in each stack. In each navigation stack, the first view controller is a List of items, the second is the Detail screen, where I can edit an item from the list. The first navigation stack is Items, the second one is Orders. I can navigate inside this or that navigation stack using segues. But in this case, I need to move from one navigation stack to another. And to do this not with the help of a direct segue, because this is an incorrect method and it creates certain problems, but through the Tab Bar Controller. For example, to start to create an order, I can go from VC2.2 to VC1.1 using an index:         tabBarController?.selectedIndex = 0 And how to return back from VC1.1 to VC 2.2 via Tab Bar Controller and pass data?
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749
Nov ’22
What happens when I use a segue?
Please, help me to understand one line of code.     override func prepare(for segue: UIStoryboardSegue, sender: Any?) {               if segue.identifier == "toDetailScreenSegue" { let detail = segue.destination as! DetailScreenViewController         detail.name = item.name         }     } What is happening in this line of code below? let detail = segue.destination as! DetailScreenViewController Is a copy of the DetailScreenViewController class being made? And since this is a class, not a structure, then not a separate copy is created, but a reference to the DetailScreenViewController class? Is this right?
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517
Oct ’22
Constraints don't work (UIKit)
I want to programmatically set the constraints for the view. I'm using the code from Apple's Swift library: Creating layout anchors // Get the superview's layout let margins = view.layoutMarginsGuide // Pin the leading edge of myView to the margin's leading edge myView.leadingAnchor.constraint(equalTo: margins.leadingAnchor).isActive = true Link But my code doesn't work. import UIKit class ViewController: UIViewController {     var myView = UIView()     override func viewDidLoad() {         super.viewDidLoad()         myView.frame.size.width = 100         myView.frame.size.height = 100         myView.backgroundColor = .green         view.addSubview(myView)         let margins = view.layoutMarginsGuide         myView.trailingAnchor.constraint(equalTo: margins.trailingAnchor).isActive = true     } } I am not getting any error messages. But my view always stays in the same place, in the upper left corner. Even if I change the constraint to center or bottom, the view doesn't move. Could you tell me what is wrong in my code?
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1.4k
Mar ’22
How to call a view in SwiftUI?
Hello everyone, recently I started to learn the SwiftUI. Now I have this code but I don't understand how can I call a view in canvas? At the first case I have error which says that argument is missing. import SwiftUI struct EmployeeDetails: View {     var employee: Employee     var body: some View {         VStack(alignment: .leading) {             Text(employee.name)                 .font(.largeTitle)                 .foregroundColor(.primary)             Text(employee.jobTitle)                 .foregroundColor(.secondary)             EmailAddress(address: employee.emailAddress)         }     } } struct EmployeeDetails_Previews: PreviewProvider {     static var previews: some View {         EmployeeDetails()     } } And when I use "employee" like argument in brackets, I have another error - can't find employee in scope. struct EmployeeDetails_Previews: PreviewProvider {     static var previews: some View {         EmployeeDetails(employee)     } } Please, help me to understand how can I call that view?
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989
Feb ’22
Why is the Button not working? SwiftUI
I want to create a button, but for some reason it does not work. The text message is not printed in the console. import SwiftUI struct Test: View {     var body: some View {         NavigationView {             Text("My Test")                 .navigationTitle("Welcome")                 .toolbar {                     Button("Help") {                         print("Help tapped!")                     }                 }         }     } } struct Test_Previews: PreviewProvider {     static var previews: some View {         Test()     } }
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4.0k
Jan ’22
The top of the table view is black
For some reason, the top of my table view in the storyboard has turned black. This is where the navbar and dynamic cell are. This happened after I tried to customize the appearance of the table view by changing the values of two options - Style and Separator (the screenshot) How do I get back the regular light color of the top of the table view? Xcode 13.2, macOS Monterey 12.1
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478
Dec ’21
Why isn't a new room created in the Rooms project? SwiftUI, WWDC19-204
Hi everyone, I want to perform the tutorial from video WWDC19 - 204. Here is an example of building the "Rooms" application. At 42 minutes, the author of the video, Jacob Xiao, shows how to add a new room. But when I try to repeat it, nothing happens. The new room is not added. My code and code of Jacob Xiao are the same. import SwiftUI struct ContentView: View {     @ObservedObject var store = RoomStore()     // Instead of //var rooms: [Room] = []     // @ObservedObject is instead of @ObjectBinding     var body: some View {         NavigationView {             List {                 Button(action: addRoom) {                     Text("Add Room")                 }                 ForEach(store.rooms) { room in                     RoomCell(room: room)                 }             }             .navigationBarTitle(Text("Rooms"))         }     }     func addRoom() {         store.rooms.append(Room(name: "Hall 2", capacity: 2000))     } } struct ContentView_Previews: PreviewProvider {     static var previews: some View {         ContentView(store: RoomStore(rooms: testData))     } } struct RoomCell: View {     var room: Room     var body: some View {         NavigationLink(destination: RoomDetail(room: room)) {             Image(room.thumbnailName)                 .cornerRadius(8)             VStack(alignment: .leading) {                 Text(room.name)                 Text("\(room.capacity) people")                     .font(.subheadline)                     .foregroundColor(.secondary)             }         }     } } My project has also an image named "Hall 2". What could be the reason that a new room is not being added? Any ideas, please.
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1.1k
Oct ’21
Checkmarks are not removed from the table cell
I want to mark the items in the list with checkmarks. But some kind of error occurs because the checkmark is installed, but not removed. Why is this happening? This is a Model: import UIKit struct Food: Codable {     var name: String     var isSelected: Bool = false } This is a TableViewController: import UIKit class SelectFoods: UITableViewController {     var foods = [Food]()     override func viewDidLoad() {         super.viewDidLoad()         foods = loadRealOrDemoData() // Load data     }     // MARK: - Table view data source     override func numberOfSections(in tableView: UITableView) -> Int {         return 1     }     override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {         return foods.count     }     override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {         let cell = tableView.dequeueReusableCell(withIdentifier: "selectFood", for: indexPath)         let food = foods[indexPath.row]         cell.textLabel?.text = food.name         // Assign checkmark from the selected item to the cell         if food.isSelected {             cell.accessoryType = .checkmark         } else {             cell.accessoryType = .none         }         cell.selectionStyle = .none         return cell     }     // MARK: - Select Food     override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {         // Create variable and check it.         guard let cell = tableView.cellForRow(at: indexPath) else { return }          //Clean cell format before select         cell.accessoryType = .none         // Get an item         var item = foods[indexPath.row]         // Set checkmark         if item.isSelected == false {             cell.accessoryType = .checkmark             item.isSelected.toggle()         // Remove checkmark         } else {             cell.accessoryType = .none             item.isSelected.toggle()         }     } }
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1.7k
Sep ’21
Why isn't the date assigned to the object property?
I am using a date picker and want to assign the value from it to an object property. But for some reason this does not happen and the object property contains nil. I put code next to it where a date value is assigned to a simple property. It works. Please tell me what's the matter here? How do I store a date into a property of an object? import UIKit struct NewDate {     var date: Date? } class MyViewController: UIViewController {         var newDate: NewDate?         @IBOutlet weak var pickerOutlet: UIDatePicker!         override func viewDidLoad() {         super.viewDidLoad()         let date = pickerOutlet.date         print(date) // Prints: 2021-09-03 03:56:17 +0000         newDate?.date = pickerOutlet.date         print(newDate?.date) // Prints: nil     } }
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721
Sep ’21
How to perform extract subview operation?
Hi everyone, I want to perform the tutorial from video WWDC19 - 204. Here is an example of building the "Rooms" application. At 11 minutes, the author of the video, Jacob Xiao, shows how he performs the extract subview operation. But when I try to repeat this operation an error occurs - Cannot find 'room' in scope. My code and code of Jacob Xiao are the same. import SwiftUI struct ContentView: View {     var rooms: [Room] = []         var body: some View {         NavigationView {                         List(rooms) { room in                 ExtractedView()             }                       .navigationBarTitle(Text("Rooms"))         }     } } struct ContentView_Previews: PreviewProvider {     static var previews: some View {         ContentView(rooms: testData)     } } struct ExtractedView: View {     var body: some View {         NavigationLink(             destination: Text(room.name)) { // Cannot find 'room' in scope             Image(room.thumbnailName)                 .cornerRadius(8)             VStack(alignment: .leading) {                 Text(room.name)                 Text("\(room.capacity) people")                     .font(.subheadline)                     .foregroundColor(.secondary)             }         }     } } I think the reason is that SwiftUI on my computer is a newer version, so some of the previous functions may not work. Could you tell me how to perform this subview extract operation today?
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3k
Aug ’21
How to Choose the WatchLandmarks target in SwiftUI Tutorial?
Hi everyone, I am studying SwiftUI on the Apple tutorial - https://developer.apple.com/tutorials/swiftui/creating-a-macos-app. In the Creating a MacOS App chapter in section 3 Update a Row View, there is a following instruction: Step 6 Choose the WatchLandmarks target to see a watchOS preview of the list. How to do this? It should be easy and simple, but somehow I haven't found it.
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571
Apr ’21