I'm trying to use a custom segue (at bottom) to present a view controller modally with a blur view. I need to instantiate the view controller with properties before I present the view controller.
Instating the VC works great when I am using pushVC, but when I use perform segue with identifier, I don't see an option to choose an already instantiated VC.
CustomViewController* VC = [self.navigationController.storyboard instantiateViewControllerWithIdentifier:#"customVC"];
[self.navigationController performSegueWithIdentifier:#"blurSegue" sender:self];
How can I perform the custom segue and force it to use the view controller I allocated (called VC above)?
https://github.com/AlvaroFranco/AFBlurSegue
I need to instantiate the view controller with properties before I
present the view controller.
Why do you have to instantiate CustomViewController before triggering the segue. That shouldn't be necessary, if you need access to a property of CustomViewController before it's shown, you can set it in prepareForSegue.
Try this:
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([segue.identifier isEqualToString:#"blurSegue"]) {
CustomViewController *customViewController = (CustomViewController *)segue.destinationViewController;
customViewController.propertyToSet = XXX; // set the property here
}
}
Ah, by the way, instead of
[self.navigationController performSegueWithIdentifier:#"blurSegue" sender:self];
just use:
[self performSegueWithIdentifier:#"blurSegue" sender:self];
Related
I have a UIPageViewController and have a button in it. Whenever the button is pressed I want to perform a Segue from the parent view controller (which has a navigation controller embedded) to the next view controller in the navigation stack. I also want to be able to pass data through the segue. I've tried a couple of things but I'm very new to iOS development and have not been successful at all.
You need to select the segue in your storyboard and give it a unique identifier and the put that in the code below.
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
if ([segue.identifier isEqualToString:#"YourSegueIdentifier"]) {
// get a reference to the destination View Controller
UIViewController *destinationVC = [segue destinationViewController];
XXYourViewControllerSubclass *yourVC = (XXYourViewControllerSubclass*)destinationVC;
// create the data and pass it to the view controller
id someData = // create your data (unless you have a property holding it already)
[yourVC acceptData:(id)someData]; // make a public method on your VC subclass to accept the data
}
// after this method has returned the seque will be performed
}
Does that make sense?
I have three classes :
1.TyphoonViewController
2.WaterTableNaviController
3.WaterTableViewController
I am trying to pass a string from the first one to the last. But I only pass the string from the first to the second. It will be a black screen when I present the third ViewController.
I've tried to make the WaterTableViewController be the root of WaterTableNaviController in storyboard.
It did present screen, but the string wasn't passed.
From TyphoonViewController
- (IBAction)ParseBut:(id)sender {
WaterTableNaviViewController *vc = (WaterTableNaviViewController *)[self.storyboard instantiateViewControllerWithIdentifier:#"WaterTableNavi"];
[vc setUrl:#"My String"];
[self presentViewController:vc animated:YES completion:nil];
}
From WaterTableNaviController
- (void)viewDidAppear:(BOOL)animated{
[super viewDidAppear:YES];
WaterTableViewController* vc = (WaterTableViewController*)[self.storyboard instantiateViewControllerWithIdentifier:#"WaterTable"];
[vc setParseUrl:m_url];
[self.navigationController pushViewController:vc animated:YES];
}
The code you have in the navigation controller is wrong - if the WaterTableVC is the root view controller of the navigation controller, it's already been instantiated, so you shouldn't do it again. Also, you don't push to the root view controller. You don't need to subclass the navigation controller at all to do what you are trying to do here. You should make a modal segue from the button in TyphoonViewController to the navigation controller, and make WaterTableViewController the root view controller of that navigation controller. The button should not have any action method, because it triggers the segue directly. Instead, you should have the following code in prepareForSegue,
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
UINavigationController *nav = segue.destinationViewController;
WaterTableViewController *waterTableVC = (WaterTableViewController *)nav.topViewController;
[waterTableVC setURL:#"My String"];
}
You can simply make another singleton class and put a property that can contain that string, so wherever you are, you can read that property
I have code that uses Storyboards for seques, like so:
- (void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([segue.identifier isEqualToString:#"ShowDiagnosis"])
{
[segue.destinationViewController setHappiness:self.diagnosis];
}
...
But I want to do it programmatically. I have myViewController class and when I click on a button I want to animate and push to myUINavigationController.
How is this done programmatically?
First things first, a segue cannot be created programmatically. It is created by the storyboard runtime when it is time to perform. However you may trigger a segue, which is already defined in the interface builder, by calling performSegueWithIdentifier:.
Other than this, you can provide transitions between view controllers without segue objects, for sure. In the corresponding action method, create your view controller instance, either by allocating programmatically or instantiating from storyboard with its identifier. Then, push it to your navigation controller.
- (void)buttonClicked:(UIButton *)sender
{
MyViewController *vc = [self.storyboard instantiateViewControllerWithIdentifier:#"my-vc-identifier"];
// OR MyViewController *vc = [[MyViewController alloc] init];
// any setup code for *vc
[self.navigationController pushViewController:vc animated:YES];
}
First of all segue can be used only with if you have a UINavigationController that will handle the navigation (push, pop, etc).
So if you have a UINavigationController and you want to push another UIViewController on the stack without using segue then you can use pushViewController:animated: method which also has a reverse popViewControllerAnimated:. Also UINavigationController provides other methods for adding/removing UIVIewControllers, for more info check UINavigationController class reference.
Before storyboards I was able to set delegates and datasources just by dragging an outlet to a class. With storyboards, I cannot drag the outlet to another view controller; there is no destination that will respond to it.
If I click on a view controller object, I am able to see the class owner at the bottom, but as soon as I select the other view controller containing the outlet, the old selection is gone, so I cannot connect the two.
Is this Apple's way of saying we should only connect them programmatically?
Correct. Set the delegate or other data in your prepareForSegue:sender: method. Here is an example:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
// Check the segue identifier
if ([segue.identifier isEqualToString:#"showDetail"])
{
// Get a reference to your custom view controller
CustomViewController *customViewController = segue.destinationViewController;
// Set your custom view controller's delegate
customViewController.delegate = self;
}
}
If your storyboard segue destination View Controller is an UIViewController then #Marco answer is right. But if your destination View Controller is a UINavigationViewController then you have to get the UIViewController from UINavigationViewController :
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
// Check the segue identifier
if ([segue.identifier isEqualToString:#"chooseCategoryType"])
{
// Get a reference of your custom view controller if your segue connection is an UIViewController
// CustomViewController *customViewController = segue.destinationViewController;
// Get a reference of your custom view controller from navigation view controller if your segue connection is an UINavigationViewController
CustomViewController *customViewController = [[[segue destinationViewController] viewControllers] objectAtIndex:0];
// Set your custom view controller's delegate
customViewController.delegate = self;
}
}
I was wondering how to properly use the storyboard to put up a view controller modally. Personally I prefer working with xibs, but it seems that the storyboard is gaining popularity and will be the way to go in the future.
The way I would normally put up a view controller modally would be like this: let's say we have ViewControllerA (A for short) and ViewControllerB (B for short).
I would then normally put a protocol in B.h specifying the delegate method when B wants to be dismissed and add the id<theProtocol> delegate field as an assign property. Assuming i'm busy in A and I want to present B modally, I would write:
B* b = [[B alloc] initWithNibName:#"B" bundle:nil];
b.delegate = self;
[self presentModalViewController:B animated:YES];
Using the storyboard, I know it's possible to put up a different view controller in a modal way by ctrl-dragging from a button to a viewcontroller and selecting modal as transition type. I'm just wondering though; where do I set the delegate of the new view controller? What's the correct practice of passing things to your modal view controller? I don't really know what the whole deal with Segues is...
Take a look at this tutorial
According to it, you should set the delegate as follows:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([segue.identifier isEqualToString:#"AddPlayer"])
{
UINavigationController *navigationController =
segue.destinationViewController;
PlayerDetailsViewController
*playerDetailsViewController =
[[navigationController viewControllers]
objectAtIndex:0];
playerDetailsViewController.delegate = self;
}
}
Where #"AddPlayer" is the name of your 'modal' segue
Instead of using the navigation controller you could directly use the UIStoryboardSegue object passed in prepareForSegue. It has a property called destinationViewController which is the view controller that is being instantiated. I find that a lot cleaner.
This is an example.
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([segue.identifier isEqualToString:#"AddPlayer"])
{
PlayerDetailsViewController
*playerDetailsViewController =
(PlayerDetailsViewController *) segue.destinationViewController;
playerDetailsViewController.delegate = self;
}
}
IMO I think that storyboards are great because they function like a blueprint of your application. Also I've never liked nibs. =D