I have to push a new segue when a button is pressed. But i also have an action attached to it that needs to be triggered before the segue is pushed.
Can you tell me how to separate them from each other? Any help would be appreciated.
Make the segue directly from one view controller to the other instead of connecting it to the button. Give it a meaningful name.
Then, in your button's action method, perform whatever you need to do first, then perform the segue using your view controller's performSegueWithIdentifier: method, using the meaningful name you chose earlier.
From your comments, it seems like you're trying to set properties on the view controller that is about to appear from your segue. If this is the case, you should implement prepareForSegue:, and use segue.destinationViewController to get a pointer to the view controller that is about to appear.
Related
Background
I am developing an application which contains a top nav bar with an icon that allows to go back to the main ViewController.
As there as several ViewControllers, I don't want to duplicate the segue on each ViewController. I would prefer to create a custom class for the top nav bar and be able to programmatically present the main ViewController. I found that I could maybe call present(viewControllerToPresent:animated:completion)
Questions
Is this the right way to do it?
How do I access the controller I need to pass to this function?
Is there a method which allows to get the controller from its title?
Also, as the main ViewController has already been instantiated when the application started, do I need to instantiate a new one or can I get a reference to the existing one?
So if I get this correct you click mainVC->firstVC->secondVC->nthVC and then you'd want to go directly back to mainVC ? View controllers are stacked so what I'd do is just dismiss all those view controllers that are above mainVC.
I have some code that opens a popover window that displays some text. This is done by an action segue rather than actual code in a storyboard. Is there any way, that I can load into a different view by pressing a button on the popover view and have it load into the next view? I've tried using another action segue, but it puts a popover into my current popover over the button that I press. Thanks!
This kind of thing can't be done with just storyboards; some code will be necessary.
Here's how I would do this: instead of trying to use two separate popovers, use one popover with kind of a "nested" setup. The popover's content view controller would contain, say, a Page1ViewController and a Page2ViewController. When first displayed, the main controller would install page 1's view. You could maybe wire the action from page 1's button directly to the main controller, but I recommend that you use delegation for this. Create a protocol that's something like Page1ViewControllerDelegate and adopt the protocol in your main controller, then in the delegate method for page1ControllerRequestTransition(_:) or whatever you choose, just grab the page 1 view out and swap the page 2 view in. You can even have the two views be different sizes; the popover will automatically adjust itself.
Oh, and don't forget to disable translatesAutoresizingMaskIntoConstraints and add appropriate constraints to fix the four sides of each page's view.
I am making an app where the user inputs some numbers into a text field and it shoots out an answer on a label. I have the answer being displayed on another view controller. Using the same prepare for segue methods on all of the screens that I have only some of them work. The others will pass whatever text I have in the first view controller label (I have checked this by inputting all sorts of stuff and it shows up on the other side)... I have also deleted the segue and made sure that the calculation works and the label in the first view controller is getting the information.
This leads me to believe that the way it is set up is fine, but the segue happens so fast that the label on the first view controller will still have the original text when the segue is performed, sending that information over as a string instead of the answer...
Is it possible to change this? It would be the only logical thing that makes sense to me write at the moment. If it is possible how could this be fixed?
Any help would be appreciated. Thanks
EDIT:
This is the whole code I was Asked To post to help figure this out
So if in the first view controller I put a '?' for the text in the label just to hold the label, and in the second view controller I put a '!' in the answer label to hold the label.. The second view controller after I run the simulator the second view controller will show a ? the text from the 1st label... so it does show that it is pushing the data over, it is just not pushing the information in the label.
I think you have a made a segue to another view controller from the same button , with which you are performing the #IBAction func usednroicalc(sender: AnyObject), what you have to do is make a segue from view controller to another view controller in storyboard , give your segue an identifier and inside the #IBAction write at the place where you want to perform the segue , that is after your calculations write , self.performseguewithIdentifier("your identifier") . you can give identifier to segue by clicking on it and than find the identifier label in the inspector.
EDIT:
Here I have dragged from ViewController the one Highlighted as yellow in ViewController Scene to TableViewController the one above first responder in TableView Controller Scene.
Just wanted to answer my own question as I have found a way to push the info over finally...
You have to set up the calculations of the code in the prepare for segue and not in the button action. The button action is now only setup for the segue to the new view controller. not the way I wanted everything thing to go but it works.
Thanks everyone for the feedback... hope this helps someone else in the future.
I'm trying to execute code when a button is pressed for an application but I can't find how to change the views after the code is executed. Is there a way to switch views how I want to or is there another way? Thank you in advanced, I'm very new to xcode.
edit: I'm trying to go from one view to another, not the view controller and yes I have one storyboard that I planned on using for the whole project if possible.
To execute code when a button is pressed, you have to set up a method that the button is hooked into. Because you said you're using storyboards, I'll assume your button is on the storyboard. Go to the assistant editor, hold ctrl, and click-and-drag from the button to the view controller's .m file (#implementation section). This will create an IBAction method, and any code in this method will execute whenever you press the button.
The method will look like this:
- (IBAction)aButtonPress:(id)sender {
}
According to your comments, you say you only want to change the on-screen view, and not transition from one view to the next.
Views are added and removed with the following methods:
[aSuperview addSubview:aSubview];
[aSubview removeFromSuperview];
I can't really tell you much else with a lot more detail from you... and even though I asked twice in the comments and you said you only want to change the view, not the view controller... I think you probably need to transition to a new view controller. Impossible to know for sure as you've given almost no detail...
But if you want to transition between view controllers (which also transitions views), then ...
Create two view controllers on the storyboard. Hook them together with a segue, and give that segue a name. Now, to perform that segue in code:
[self performSegueWithIdentifier:#"YOUR_SEGUE_NAME" sender:self];
i am trying to switch between two view controllers using storyboard. I create a modal seague by control-dragging (on buttons) from 1st view controller to 2nd, and then from the 2nd to the first.
So whenever I click on a button in 1st VC, it takes me to the 2nd VC. This time when i click the button on second VC, does it take me back to the original instance of the 1st VC or it creates a new instance?
If it takes me to the same instance, and user had written some data in some textfields, is there anyway to retain that on screen? (I might want to save them in some variables, and since the program will return back to the same instancem i'll be able to get the variables back)
If it doesn't take me to the same instance, is there any method to do so?
I tried making an instance of 2nd VC and using self.navigarionController push...(instance) but this doesn't swtich the controller.
If i do this pushing using the storyboard, and i do pop in my 2nd VC, it doesn't get popped either.
(and i would also couldn't understand the difference between push,modal and custom seagues)
Create the modal segue from VC1's button to VC2, but not the reverse one. When the VC2's button is tapped, call dismissViewControllerAnimated:completion: to return to where you were.
If you used a push segue instead, you would call popViewControllerAnimated: to go back but that only works if you have your view controllers managed by a UINavigationController.
You can think of push as a way of stepping through a sequence of related scenes while modal is something that's a bit out of the normal flow of the application. (That's not a firm rule but it's a starting point for deciding which way to go.) For 'custom', you write the segue code, so you decide what happens.