I have an app that uses a main screen (below) and then a barcode scanner framework to scan in a barcode and then I will code an action to perform. However, the problem I am having is that in the code it takes me back to the scanning screen. I have tried to use present(VC1, animated: true, completion: nil) and it does not know what VC1 is.
I assigned VC1 in Xcode under storyboard id (see below):
Below is my code here for view controller.swift. Now the code takes you back to the scanning screen, but I want to go back to VC1 the main view controller.
import UIKit
import BarcodeScanner
var presentedViewController: UIViewController?
final class ViewController: UIViewController {
#IBOutlet var pushScannerButton: UIButton!
//Present view and handle barcode scanning
#IBAction func handleScannerPush(_ sender: Any, forEvent event: UIEvent) {
let viewController = makeBarcodeScannerViewController()
viewController.title = "Barcode Scanner"
present(viewController, animated: true, completion: nil)
}
private func makeBarcodeScannerViewController() -> BarcodeScannerViewController {
let viewController = BarcodeScannerViewController()
viewController.codeDelegate = self
viewController.errorDelegate = self
viewController.dismissalDelegate = self
return viewController
}
}
// MARK: - BarcodeScannerCodeDelegate
extension ViewController: BarcodeScannerCodeDelegate {
func scanner(_ controller: BarcodeScannerViewController, didCaptureCode code: String, type: String) {
print("Barcode Data: \(code)")
print("Symbology Type: \(type)")
controller.dismiss(animated: true, completion: nil)
// DispatchQueue.main.asyncAfter(deadline: .now() + 5.0) {
// controller.resetWithError()
// }
}
}
// MARK: - BarcodeScannerErrorDelegate
extension ViewController: BarcodeScannerErrorDelegate {
func scanner(_ controller: BarcodeScannerViewController, didReceiveError error: Error) {
print(error)
}
}
// MARK: - BarcodeScannerDismissalDelegate
extension ViewController: BarcodeScannerDismissalDelegate {
func scannerDidDismiss(_ controller: BarcodeScannerViewController) {
controller.dismiss(animated: true, completion: nil)
}
}
Related
I've followed the instructions here but I'm still unsure about this part:
modalVC.delegate=self;
self.presentViewController(modalVC, animated: true, completion: nil)
I've tried instantiating the view controller programmatically but still to no avail.
here's my code for when dismissing the modal view controller:
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
self.dismiss(animated: true) {
//
}
}
I'm using storyboard to segue with modal view.
This is the data I wish to transfer back to the parent view controller:
var typeState = "top"
var categoryState = "casual"
Which are two String values.
I've tried to pass data from the modal view controller as shown:
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
self.dismiss(animated: true, completion: nil)
delegate?.sendValue(value: "success")
if let presenter = presentingViewController as? OOTDListViewController {
presenter.receivedValue = "test"
}
}
whereas on the parent view controller I did as such:
func sendValue(value: NSString) {
receivedValue = value as String
}
#IBAction func printReceivedValue(_ sender: UIButton) {
print(receivedValue)
}
I still couldnt receive any value when I hit the print button.
Modal view controller:
protocol ModalViewControllerDelegate
{
func sendData(typeState: String, categoryState: String)
}
var delegate:ModalViewControllerDelegate!
var typeState = "top"
var categoryState = "casual"
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
self.dismiss(animated: true, completion: nil)
delegate?.sendData(typeState: typeState as String, categoryState: categoryState as String)
}
Parent view controller:
class parentViewController: UICollectionViewController, ModalViewControllerDelegate {
var typeState: String?
var categoryState: String?
func sendData(typeState: String, categoryState: String) {
self.typeState = typeState as String
self.categoryState = categoryState as String
}
#IBAction func printReceivedValue(_ sender: UIButton) {
print(typeState)
}
Here's my new code without using delegate method:
Modal view Controller:
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
self.dismiss(animated: true, completion: nil)
if let presenter = presentingViewController as? OOTDListViewController {
presenter.typeState = typeState
presenter.categoryState = categoryState
}
}
OOTDListViewController:
#IBAction func presentModalView(_ sender: UIBarButtonItem) {
let modalView = storyboard?.instantiateViewController(withIdentifier: "filterViewController") as! ModalViewController
let navModalView: UINavigationController = UINavigationController(rootViewController: modalView)
self.present(navModalView, animated: true, completion: nil)
}
#IBAction func printValue(_ sender: UIButton) {
print(typeState)
print(categoryState)
}
Depending on the data you want to pass, you can create a property in the presenting view controller, which you can set when dismissing the modal view controller, so you can spare yourself the delegate.
For example, you have a ContactsViewController, holding a var contacts: [Contact] = [] property. When you want to create a new contact, you present a modal view controller with the different values you need to create a new Contact object. When you are done and want to dismiss the view controller, you call the function as you did in your code, but set the property in the ContactsViewController. It will look something like this:
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
if let presenter = presentingViewController as? ContactsViewController {
presenter.contacts.append(newContact)
}
dismiss(animated: true, completion: nil)
}
If you don't want to use a delegate, this is how you go about it:
In your OOTDListViewController :
var testValue: String = ""
#IBAction func printReceivedValue(_ sender: UIButton) {
print(testValue)
}
In your modal view controller (I'll call it PresentedViewController) :
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
// if your OOTDListViewController is part of a UINavigationController stack, this check will probably fail.
// you need to put a breakpoint here and check if the presentingViewController is actually a UINavigationController.
// in that case, you will need to access the viewControllers variable and find your OOTDListViewController
if let presenter = presentingViewController as? OOTDListViewController {
presenter.testValue = "Test"
}
dismiss(animated: true, completion: nil)
}
If you want to use a delegate, this is how to do it:
In your OOTDListViewController:
protocol ModalDelegate {
func changeValue(value: String)
}
class OOTDListViewController: ModalDelegate {
var testValue: String = ""
#IBAction func presentViewController() {
// here, you either create a new instance of the ViewController by initializing it, or you instantiate it using a storyboard.
// for simplicity, I'll use the first way
// in any case, you cannot use a storyboard segue directly, bevause you need access to the reference of the presentedViewController object
let presentedVC = PresentedViewController()
presentedVC.delegate = self
present(presentedVC, animated: true, completion: nil)
}
func changeValue(value: String) {
testValue = value
print(testValue)
}
}
In your PresentedViewController:
class PresentedViewController {
var delegate: ModalDelegate?
var testValue: String = ""
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
if let delegate = self.delegate {
delegate.changeValue(testValue)
}
dismiss(animated: true, completion: nil)
}
}
If using a navigation controller you will have to first grab the UINavigation Controller and then get the correct ViewController from the Navigation Controller stack.
Here's how my code looked in that case.
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
if let navController = presentingViewController as? UINavigationController {
let presenter = navController.topViewController as! OOTDListViewController
presenter.testValue = "Test"
}
dismiss(animated: true, completion: nil)
}
I am using the a tab bar so the working code is as below:
if let tabBar = self.presentingViewController as? UITabBarController {
let homeNavigationViewController = tabBar.viewControllers![0] as? UINavigationController
let homeViewController = homeNavigationViewController?.topViewController as! HomeController
homeViewController._transferedLocationID = self.editingLocationID!
}
You need to call the delegate method in dismissViewController method
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
delegate?.sendData(typeState: "top", categoryState: "casual")
self.dismiss(animated: true) {
//
}
}
in you Modal ViewController class create delegate
weak var delegate: MyProtocol?
create a protocol with the method name sendData in MyProtocol and in your presentingViewController where you are assigning the delegate, implement the MyProtocol method
protocol MyProtocol: AnyObject {
func sendData(typeState: String, categoryState: String)
}
class ViewController: UIViewController, MyProtocol {
var typeState: String?
var categoryState: String?
override func viewDidApear() {
super.viewDidApear()
presentNewModalVC()
}
func presentNewModalVC() {
let modalVC = NewModalViewControllerToBePresented()
modalVC.delegate = self
present(modalVC, animated: true)
}
func sendData(typeState: String, categoryState: String) {
self.typeState = typeState
self.categoryState = categoryState
}
}
I've followed the instructions here but I'm still unsure about this part:
modalVC.delegate=self;
self.presentViewController(modalVC, animated: true, completion: nil)
I've tried instantiating the view controller programmatically but still to no avail.
here's my code for when dismissing the modal view controller:
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
self.dismiss(animated: true) {
//
}
}
I'm using storyboard to segue with modal view.
This is the data I wish to transfer back to the parent view controller:
var typeState = "top"
var categoryState = "casual"
Which are two String values.
I've tried to pass data from the modal view controller as shown:
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
self.dismiss(animated: true, completion: nil)
delegate?.sendValue(value: "success")
if let presenter = presentingViewController as? OOTDListViewController {
presenter.receivedValue = "test"
}
}
whereas on the parent view controller I did as such:
func sendValue(value: NSString) {
receivedValue = value as String
}
#IBAction func printReceivedValue(_ sender: UIButton) {
print(receivedValue)
}
I still couldnt receive any value when I hit the print button.
Modal view controller:
protocol ModalViewControllerDelegate
{
func sendData(typeState: String, categoryState: String)
}
var delegate:ModalViewControllerDelegate!
var typeState = "top"
var categoryState = "casual"
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
self.dismiss(animated: true, completion: nil)
delegate?.sendData(typeState: typeState as String, categoryState: categoryState as String)
}
Parent view controller:
class parentViewController: UICollectionViewController, ModalViewControllerDelegate {
var typeState: String?
var categoryState: String?
func sendData(typeState: String, categoryState: String) {
self.typeState = typeState as String
self.categoryState = categoryState as String
}
#IBAction func printReceivedValue(_ sender: UIButton) {
print(typeState)
}
Here's my new code without using delegate method:
Modal view Controller:
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
self.dismiss(animated: true, completion: nil)
if let presenter = presentingViewController as? OOTDListViewController {
presenter.typeState = typeState
presenter.categoryState = categoryState
}
}
OOTDListViewController:
#IBAction func presentModalView(_ sender: UIBarButtonItem) {
let modalView = storyboard?.instantiateViewController(withIdentifier: "filterViewController") as! ModalViewController
let navModalView: UINavigationController = UINavigationController(rootViewController: modalView)
self.present(navModalView, animated: true, completion: nil)
}
#IBAction func printValue(_ sender: UIButton) {
print(typeState)
print(categoryState)
}
Depending on the data you want to pass, you can create a property in the presenting view controller, which you can set when dismissing the modal view controller, so you can spare yourself the delegate.
For example, you have a ContactsViewController, holding a var contacts: [Contact] = [] property. When you want to create a new contact, you present a modal view controller with the different values you need to create a new Contact object. When you are done and want to dismiss the view controller, you call the function as you did in your code, but set the property in the ContactsViewController. It will look something like this:
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
if let presenter = presentingViewController as? ContactsViewController {
presenter.contacts.append(newContact)
}
dismiss(animated: true, completion: nil)
}
If you don't want to use a delegate, this is how you go about it:
In your OOTDListViewController :
var testValue: String = ""
#IBAction func printReceivedValue(_ sender: UIButton) {
print(testValue)
}
In your modal view controller (I'll call it PresentedViewController) :
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
// if your OOTDListViewController is part of a UINavigationController stack, this check will probably fail.
// you need to put a breakpoint here and check if the presentingViewController is actually a UINavigationController.
// in that case, you will need to access the viewControllers variable and find your OOTDListViewController
if let presenter = presentingViewController as? OOTDListViewController {
presenter.testValue = "Test"
}
dismiss(animated: true, completion: nil)
}
If you want to use a delegate, this is how to do it:
In your OOTDListViewController:
protocol ModalDelegate {
func changeValue(value: String)
}
class OOTDListViewController: ModalDelegate {
var testValue: String = ""
#IBAction func presentViewController() {
// here, you either create a new instance of the ViewController by initializing it, or you instantiate it using a storyboard.
// for simplicity, I'll use the first way
// in any case, you cannot use a storyboard segue directly, bevause you need access to the reference of the presentedViewController object
let presentedVC = PresentedViewController()
presentedVC.delegate = self
present(presentedVC, animated: true, completion: nil)
}
func changeValue(value: String) {
testValue = value
print(testValue)
}
}
In your PresentedViewController:
class PresentedViewController {
var delegate: ModalDelegate?
var testValue: String = ""
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
if let delegate = self.delegate {
delegate.changeValue(testValue)
}
dismiss(animated: true, completion: nil)
}
}
If using a navigation controller you will have to first grab the UINavigation Controller and then get the correct ViewController from the Navigation Controller stack.
Here's how my code looked in that case.
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
if let navController = presentingViewController as? UINavigationController {
let presenter = navController.topViewController as! OOTDListViewController
presenter.testValue = "Test"
}
dismiss(animated: true, completion: nil)
}
I am using the a tab bar so the working code is as below:
if let tabBar = self.presentingViewController as? UITabBarController {
let homeNavigationViewController = tabBar.viewControllers![0] as? UINavigationController
let homeViewController = homeNavigationViewController?.topViewController as! HomeController
homeViewController._transferedLocationID = self.editingLocationID!
}
You need to call the delegate method in dismissViewController method
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
delegate?.sendData(typeState: "top", categoryState: "casual")
self.dismiss(animated: true) {
//
}
}
in you Modal ViewController class create delegate
weak var delegate: MyProtocol?
create a protocol with the method name sendData in MyProtocol and in your presentingViewController where you are assigning the delegate, implement the MyProtocol method
protocol MyProtocol: AnyObject {
func sendData(typeState: String, categoryState: String)
}
class ViewController: UIViewController, MyProtocol {
var typeState: String?
var categoryState: String?
override func viewDidApear() {
super.viewDidApear()
presentNewModalVC()
}
func presentNewModalVC() {
let modalVC = NewModalViewControllerToBePresented()
modalVC.delegate = self
present(modalVC, animated: true)
}
func sendData(typeState: String, categoryState: String) {
self.typeState = typeState
self.categoryState = categoryState
}
}
I am having issues trying to pass the data back to the ViewController (from BarCodeScannerViewController to TableViewController)
SecondVC (BarCodeScannerViewController.swift):
#objc func SendDataBack(_ button:UIBarButtonItem!) {
if let presenter = self.presentingViewController as? TableViewController {
presenter.BarCode = "Test"
}
self.dismiss(animated: true, completion: nil)
}
FirstVC (TableViewController.swift):
// The result is (BarCode - )
var BarCode: String = ""
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
print("BarCode - \(BarCode)")
}
Each time ViewWillAppear is running the value is not set, what could be causing this issue?
You should use the delegate pattern. I doubt in your code above that self.presentingViewController is actually set.
An example of using the delegate pattern for this:
// BarCodeScannerViewController.swift
protocol BarcodeScanningDelegate {
func didScan(barcode: String)
}
class BarCodeScannerViewController: UIViewController {
delegate: BarcodeScanningDelegate?
#objc func SendDataBack(_ button:UIBarButtonItem!) {
delegate?.didScan(barcode: "Test")
}
}
// TableViewController
#IBAction func scanBarcode() {
let vc = BarCodeScannerViewController()
vc.delegate = self
self.present(vc, animated: true)
}
extension TableViewController: BarcodeScanningDelegate {
func didScan(barcode: String) {
print("[DEBUG] - Barcode scanned: \(barcode)")
}
}
I'm using Xcode 8 to build an application for iPhone.My simple app has an button. When user tap on this button, messageComposeViewController is called and with phone number and message content filled.The message went through successfully when I clicked on Send button.The problem is MessageComposeViewController is showing only once.After the message sent, when I tapped on the button to call it, a black screen showed up instead of the message composer.My code is attached below. I appreciate any help.
import UIKit
import MessageUI
class ViewController: UIViewController, MFMessageComposeViewControllerDelegate {
let msg = MFMessageComposeViewController()
#IBOutlet weak var coordinate_label: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
#IBAction func sendMessage(_ sender: AnyObject) {
self.msg.body = "Message Content"
self.msg.recipients = ["xxx-xxx-xxxx"]
self.msg.messageComposeDelegate = self
self.present(msg, animated: false, completion: nil)
}
func messageComposeViewController(_ controller: MFMessageComposeViewController, didFinishWith result: MessageComposeResult) {
switch result.rawValue {
case MessageComposeResult.cancelled.rawValue:
dismiss(animated: true, completion: nil)
case MessageComposeResult.failed.rawValue:
dismiss(animated: true, completion: nil)
case MessageComposeResult.sent.rawValue:
dismiss(animated: true, completion: nil)
default:
break;
}
}
}
Try this code
import Foundation
import MessageUI
let textMessageRecipients = ["1-800-867-5309"] // for pre-populating the recipients list (optional, depending on your needs)
class MessageComposer: NSObject, MFMessageComposeViewControllerDelegate {
// A wrapper function to indicate whether or not a text message can be sent from the user's device
func canSendText() -> Bool {
return MFMessageComposeViewController.canSendText()
}
// Configures and returns a MFMessageComposeViewController instance
func configuredMessageComposeViewController() -> MFMessageComposeViewController {
let messageComposeVC = MFMessageComposeViewController()
messageComposeVC.messageComposeDelegate = self // Make sure to set this property to self, so that the controller can be dismissed!
messageComposeVC.recipients = textMessageRecipients
messageComposeVC.body = "Hey friend - Just sending a text message in-app using Swift!"
return messageComposeVC
}
// MFMessageComposeViewControllerDelegate callback - dismisses the view controller when the user is finished with it
func messageComposeViewController(controller: MFMessageComposeViewController!, didFinishWithResult result: MessageComposeResult) {
controller.dismissViewControllerAnimated(true, completion: nil)
}
}
Note, latest syntax 2017 ..
func messageComposeViewController(_ controller: MFMessageComposeViewController, didFinishWith result: MessageComposeResult) {
controller.dismiss(animated: true, completion: nil)
}
In Your viewController ..
import UIKit
class ViewController: UIViewController {
// Create a MessageComposer
let messageComposer = MessageComposer()
#IBAction func sendTextMessageButtonTapped(sender: UIButton) {
// Make sure the device can send text messages
if (messageComposer.canSendText()) {
// Obtain a configured MFMessageComposeViewController
let messageComposeVC = messageComposer.configuredMessageComposeViewController()
// Present the configured MFMessageComposeViewController instance
// Note that the dismissal of the VC will be handled by the messageComposer instance,
// since it implements the appropriate delegate call-back
presentViewController(messageComposeVC, animated: true, completion: nil)
} else {
// Let the user know if his/her device isn't able to send text messages
let errorAlert = UIAlertView(title: "Cannot Send Text Message", message: "Your device is not able to send text messages.", delegate: self, cancelButtonTitle: "OK")
errorAlert.show()
}
}
}
I am implementing a seemingly trivial and very popular use case where users select a contact, and send them a precomposed SMS.
However, the SMS ViewController dismisses itself automatically. This is easily reproducible.
How do I fix this?
Here's my code:
import UIKit
import MessageUI
import ContactsUI
class ViewController: UIViewController, MFMessageComposeViewControllerDelegate, CNContactPickerDelegate{
let contactPickerViewController = CNContactPickerViewController()
let messageVC = MFMessageComposeViewController()
override func viewDidLoad() {
super.viewDidLoad()
contactPickerViewController.delegate = self
messageVC.messageComposeDelegate = self
}
func contactPicker(picker: CNContactPickerViewController, didSelectContact contact: CNContact) {
if let phoneNumberValue = contact.phoneNumbers.first?.value as? CNPhoneNumber {
if let phoneNumber = phoneNumberValue.valueForKey("digits") as? String {
// Configure message ViewController
messageVC.recipients = [phoneNumber]
messageVC.body = "Yoyoyo"
picker.presentViewController(messageVC, animated: true, completion: nil)
}
}
}
func messageComposeViewController(controller: MFMessageComposeViewController, didFinishWithResult result: MessageComposeResult) {
self.dismissViewControllerAnimated(true, completion: nil)
}
#IBAction func invite(sender: AnyObject) {
self.presentViewController(self.contactPickerViewController, animated: true, completion: nil)
}
}
The problem is that you are asking your picker to present the message view controller. When contactPicker:picker:didSelectContact: method is called, the picker view controller is automatically being dismissed by the system. This means that the view controller is going away and you are trying to use that view controller to present your next view controller.
What you need to do is have "ViewController" in this case present the message view controller. Below is an example of the portion of your code i changed. You'll notice i have a timer there. This is because if you try to present the messageVC right away, nothing will happen because the contacts view controller isn't done dismissing itself yet.
func contactPicker(picker: CNContactPickerViewController, didSelectContact contact: CNContact) {
if let phoneNumberValue = contact.phoneNumbers.first?.value as? CNPhoneNumber {
if let phoneNumber = phoneNumberValue.valueForKey("digits") as? String {
// Configure message ViewController
messageVC.recipients = [phoneNumber]
messageVC.body = "Yoyoyo"
dispatch_async(dispatch_get_main_queue(), { () -> Void in
self.presentViewController(self.messageVC, animated: true, completion: nil)
})
}
}
}