I made a segue in order to pass data. When i click the button, it does the segue. I want to manage it manually with code, for example i want an error alert to be shown, before it moves into the next view controller. I use the code below, but when i tap the button, it presents the next controller right after.
I tried this:
performSegueWithIdentifier("mysegue", sender: nil)
You can't create a segue programmatically. You can invoke one programmatically however. As Paul says, remove the segue from your button and control-drag a segue from the source view controller to the destination you controller. Give it a unique identifier. Then you can invoke the segue in code with a call to performSegueWithIdentifier
Related
I am performing a segue to open another ViewController, afterwards I go back to the initial ViewController also via performSegue.
If I am doing this, all the values in the initial ViewController (e.g. the image in the UIImageView) are destroyed.
Do I need to save everything before I perform a Segue, or am I doing something completely wrong?
Thanks!
EDIT:
This is what I would like to achieve, if I press the menu button on my "HomeVC", the tableView of the SWRevealViewController pops out from the left side. If I press a cell, I get with segue push, to another UINavigationController. From this Controller I would like to go back to the "HomeVC".
Here is a screenshot.
You do it wrong. Performing a segue will create a brand new controller from the segue's destination and present/show it.
If you want to go back, you shouldn't perform another segue. Instead, you must dismiss() it if you presented the newController modally or pop() it if you show/push it.
This tutorial may help
I just started with Xcode and Swift.
I try to build my first little App for iOS. But now I have the problem, that I don't know how to implement a the back button, so that i come back to the view before.
My Storyboard look like this:
When I open the A-Z view, I want to display the Back Arrow, which turn me back to the Item 2 view.
To open the A - Z view I connect the button "Medikamente A - Z" with the Navigation Controller.
When using storyboards the back button is usually implemented with unwind segue.
I usually like to follow raywenderlich toturials on UI related topics, like this - http://www.raywenderlich.com/113394/storyboards-tutorial-in-ios-9-part-2
It include a detailed example of how to implement back button in storyboards. Quoting from it -
Storyboards provide the ability to ‘go back’ with something called an unwind segue, which you’ll implement next.
There are three main steps:
1. Create an object for the user to select, usually a button.
2. Create an unwind method in the controller that you want to return to.
3. Hook up the method and the object in the storyboard.
When using UINavigationController, whenever you push to a new ViewController the back button will automatically appear, so you can jump back to the previous View Controller.
So it's works like:
UIViewController -> UIViewController -> UIViewController
A back button will appear on the last 2 so you can pop back the the previous ViewController.
You don't have to do any additional coding for the back button to appear, it'll do it on its own. I hope this clears it up. Let me know if you have any questions.
To implement a back button, your root view controller has to be a Navigation Controller.
The first view controller becomes the navigation root of the navigation controller.
If you want to present another view controller, you select a "Show Detail" relationship as the action for the button which should show the view controller. To do this, Ctrl-click and drag from the button to the destination view controller and select "Show Detail".
I had the same problem, even when on the storyboard the back button was visible at design time.
I deleted the segue, and recreated it with "Show" instead of "Show detail". Changing the segue to "Show" had no effect. I think this is a bug, so if you miss that back button delete and recreate the segue.
I am designing two pages, one followed by the other, in Xcode 7. Let's call them the first and second view controllers. From a button in the first view controller, with a modal segue, the second view controller shows up. I want to add a button to second view controller so that when I hit that button, I can simply exit from the second and back to the first view controller.
I know this feature can be done by navigation controller with putting cancel button to the navigation bar on second view controller which I don't want to. I want specifically a button to have that functionality.
I thought of calling the first view controller with code when the button is tapped, but it sounds me like a bad coding. So, I would like to learn what is a good way of achieving this.
Thanks,
Add method to the second view controller:
#IBAction func exitButtonPressed(sender: AnyObject) {
dismissViewControllerAnimated(true, completion: nil);
}
Next add button to the second view controller in interface builder and connect button's action to this method.
use Unwind Segues
Unwind Segues give you a way to “unwind” the navigation stack and specify a destination to go back to.
for sample tutorial1, tutorial2
My question is very similar to : Swift: Make button trigger segue to new scene
The issue is:
I have a view controller, with a button that causes another view controller to appear modally.
I have Ctrl+Click from the button to the second View Controller, and created the segue in IB.
Then I Ctrl+Click from the button again to the source code of the view controller to create an IBAction method.
I assumed that the button will do two things now: a) call the IBAction method , and b) perform the segue.
What happens is only the segue for some reason.
When I delete the segue, or remove the call to the view controller from IB, then the IBAction is called, but Xcode tells me that the second view controller is not reachable now.
I want to be able to present an ActionSheet to the user and then be able to performSegue to the second view controller, based on what the user selected from the action sheet.
I know I can programatically call performSegue but that requires the creation of the segue and attaching it to a physical button in IB, which defeats the purpose of not calling the IBAction that button may already have.
If I want to do some additional steps before calling the segue I usually attach an IBAction to the UIButton and call the perform segue from within this, in the code. You can add a segue to the storyboard and give it an ID, without having to connect it to a button. You do this by control-clicking on the viewcontroller and drag to the next viewcontroller in the storyboard.
Connecting a segue from storyboard will automatically always perform the segue. You can do any preparation for transitioning to the new view controller in the prepareForSegue method.
If there is some logic that comes before, like a user selecting something from the action sheet, just use the IBAction and then perform the segue with performSegueWithIdentifier based on the user selection. However, you do not have to create another button, just ctrl+drag from one view controller to another and give the segue an identifier.
I need to detect an unwind segue from a child to a parent view controller. I know it is possible to do this if I have a button that initiates to unwind segue, but is there a way to detect it if I just use the standard back button that is created automatically
#IBAction func unwind(segue:UIStoryboardSegue) {
println("segue did unwind")
}
I have tried by putting this into the parent view controller, and then connected (ctrl+drag) from the child view controller to exit. But this doesn't call the above method
When You want to transition to the parent screen using the Back button, do to control-drag from the button to the parent VC. Control-Drag from the button to the Exit present on the top of VC. then select your unwind segue from the list.
Hope this helps. :)