I am trying to perform a segue when the ViewController loads so it can trigger the prepareForSegue function.
I have tried using performselector but it does not work. Any suggestions?
func doSegue() {
performSegue(withIdentifier: "doSegue", sender: nil)
}
perform(Selector(("doSegue")), with: nil, afterDelay: 1)
func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
let guest = segue.destination as! WarningTableViewController
//code
}
It says it cannot find a selector named doSegue.
The code you posted is confusing.
Why there's a perform(Selector... there?
Here's a working example:
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
performSegue(withIdentifier: "doSegue", sender: self)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "doSegue" {
print("It works")
// Or call another function, e.g. "doSomethingElse()"
}
}
}
Also double-check the segue declaration in Interface Builder:
Related
My issue here is that I would like to change a UILabel's text according to which button triggered the segue. My identifier of my QuestionViewController (second view controller) is "goToQuestion", I have 2 buttons a truth and a dare button, they're both UI Buttons that can perform segues to the QuestionViewController, now the main question is how can I update the my UILabel to say Truth if the segue was performed through the truthPressed UIButton and to say dare if segue was performed through darePressed, I'm sure it requires and if and else statement that has to be in the QuestionViewController, or an " if segue.identifier = darePressed ... " I'm just confused and would like someone to enlighten me
#IBAction func truthPressed(_ sender: UIButton) {
performSegue(withIdentifier: "goToQuestion", sender: self)
}
#IBAction func darePressed(_ sender: UIButton) {
performSegue(withIdentifier: "goToQuestion", sender: self)
}
You need to override prepare(for segue:
#IBAction func truthPressed(_ sender: UIButton) {
performSegue(withIdentifier: "goToQuestion", sender: "truth")
}
#IBAction func darePressed(_ sender: UIButton) {
performSegue(withIdentifier: "goToQuestion", sender: "dare")
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if let des = segue.destination as? QuestionViewController {
des.sentValue = sender as! String
}
}
With
class QuestionViewController:UIViewController {
var sentValue = ""
override func viewDidLoad() {
super.viewDidLoad()
print(sentValue)
}
}
I'm using segue to open a new window in a xcode app.
The segue is correct, when I tap on the button the new window is shown.
I want to pass a string variable from FirstViewController to DetailViewController but I can't set the variable in the DetailViewController.
This is the code in FirstViewController:
if control == view.rightCalloutAccessoryView {
func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let controller = segue.destination as! DetailViewController
controller.Name = "test"
}
performSegue(withIdentifier: "showdetail", sender: self)
}
And this the DetailViewController code
class DetailViewController: UIViewController, WKNavigationDelegate {
var Name: String = ""
override func viewDidLoad() {
super.viewDidLoad()
print(Name)
}
}
Where am I doing wrong?
The method prepare(for must be on the top level of the class.
And please name variables according to the guidelines with starting lowercase letter
func someMethod()
{
if control == view.rightCalloutAccessoryView {
performSegue(withIdentifier: "showdetail", sender: self)
}
}
func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let controller = segue.destination as! DetailViewController
controller.name = "test"
}
}
I am trying to go to two different VC with two different buttons. With the 'newGeneratedListBtn i only want to go to vc1. With the 'newEmptyList' button i want to go to vc3 with a bool value which works. But when i click first button 'newGeneratedListBtn' to go to vc1 I get error: "Could not cast value of type 'AppName.vc1' to 'AppName.vc3'.
Seems like when i click button to vc1 it tries to send the same values as i want to send to vc3. How can i solve this?
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
let value = true
//Button to VC1
#IBAction func newGeneratedListBtn(_ sender: UIButton) {
performSegue(withIdentifier: "unwindSegueToVC1", sender: self)
}
//Value to send to VC2
override func prepare (for segue: UIStoryboardSegue, sender: Any!) {
let vc = segue.destination as! ListView
vc.newEmptyListValue = value
}
//Button to VC2
#IBAction func newEmptyList(_ sender: UIButton) {
performSegue(withIdentifier: "valueSender2", sender: self)
}
}
You need to cast for a specific identifier
override func prepare (for segue: UIStoryboardSegue, sender: Any!) {
super.prepare(for:segue,sender:sender)
if segue.identifier == "valueSender2" {
let vc = segue.destination as! ListView
vc.newEmptyListValue = value
}
else {
// it's unwindSegueToVC1
}
}
as both
performSegue(withIdentifier: "unwindSegueToVC1", sender: self)
performSegue(withIdentifier: "valueSender2", sender: self)
with call prepare
The problem is there is only one implementation of prepare(for:sender:), like this:
override func prepare (for segue: UIStoryboardSegue, sender: Any!) {
let vc = segue.destination as! ListView
vc.newEmptyListValue = value
}
Both of your segues pass through that one method. You must use a switch or other condition to figure out which segue this is, and send the info appropriate to that segue.
I have the following interfaces:
In the table view I set the new values for the user and I would like to call the function to update the data from the server when the button "Done" from the main view is pressed.
How I can do it?
I have tried:
#IBAction func doneTapped(_ sender: Any){
ProfileEditingTableViewController().updateData()
}
But all the text fields from the other view are null because it seems to be a new instance of ProfileEditingTableViewController.
updateData() can't be static.
class ProfileEditingViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
}
#IBAction func cancelButton(_ sender: Any) {
dismiss(animated: true, completion: nil)
}
#IBAction func doneTapped(_ sender: Any) {
// Here I have to save the data from the other View
dismiss(animated: true, completion: nil)
}
}
class ProfileEditingTableViewController: UITableViewController {
func updateData() {
...
}
}
This line
ProfileEditingTableViewController().updateData()
is incorrect as it creates a new instance, you need to use delegate to access the presented ProfileEditingTableViewController
class ProfileEditingTableViewController: UITableViewController {
var profileInstance: ProfileEditingViewController!
}
When you present information from profile:
let info = //
info.delegate = self // here self is the profile instance
Then use:
profileInstance.updateData()
//
Edit: connect the segue source to the vc itself ( yellow circular icon ) , this inside ( ProfileEditingViewController)
self.performSegue(withIdentifier: "goToNext", sender: nil)
//
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
super.prepare(for: segue, sender: sender)
if segue.identifier == "goToNext" {
let des = segue.destination as! ProfileEditingTableViewController
des.profileInstance = self
}
}
I have a problem with my second viewController when trying to send data with segue. The code of Login is:
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let secondView = segue.destination as! DataBaseConn
secondView.user=TextUsername.text!
secondView.pass=Pass.text!
}
override func viewDidLoad() {
super.viewDidLoad()
self.performSegue(withIdentifier: "sendData", sender: self)
}
I get the error at this line:
let secondView = segue.destination as! DataBaseConn
Both views have the custom class set.