Here's the issue, I'm trying to make an app that receives updates for different data in the same TableView (like facebook, lets say), that's not the issue however. All data has the same format, the thing is when you click on a row I want to open the corresponding view, I can identify the correct view to display. I try to use the following.
NavigationController.PushViewController (DestinationViewController, false);
When it gets triggered the objects that I created on the storyboard for the DestinationViewController appear to be null, and all the "glue" code is on the ViewDidLoad or ViewWillAppears (which is supposed to have every object instantiated)
I'm using Tab Bar Navigation Model.
PS: If I use the app and enter to my DestinationViewController it works.
So who knows an approach or has an example of something like this, or something that will get me near the place i want to go?
If you use
NavigationController.PushViewController (DestinationViewController, false);
I believe you need to allocate the view controller before you use it with
DestinationVC *vc = [DestinationVC alloc] init];
Correct me if im wrong everyone.
Also if you are using storyboards and have control dragged to different views, you should use the method
[self.navigationController performSegueWithIdentifier:#"" sender:self];
Then you can use the prepareForSegue method.
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:#"whatYouNamedItInTheStoryboard"]) {
// do stuff for this segue
} else if ([segue identifier] isEqual.......) {
}
}
Hopefully this helps your problem.
You might want to post an image of your storyboard.
I solve the issue kinda like Michael and Paul, says.
Declare a public Attribute on the ViewController.
Then passed the current ViewController to the table source, on the RowSelected Method i put the selected value on the public property of the viewController
And in the PrepareForSegue method i check which type of data it is so i can assign the appropiate segue on the segue.DestinationViewController and pass the data.
I don't know if this is the best approach but, it works good.
Related
I'm creating an app in Xcode that currently consist of a Navigation Controller a Table View Controller and a regular View Controller.
I'm using StoryBoard and have created a segue between the table view and the regular view controller. In the navigation bar I have a button that I've dragged to the view controller in the StoryBoard. When I click at the button, the new View Controller is viewed like it suppose to. I then tried to pass data from the table view controller, see below:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:#"läggTill"])
{
// Get reference to the destination view controller
AddPlayerViewController *apv = [segue destinationViewController];
[apv.myTextField setText:#"hello"];
}
}
The segue identifier is "läggTill", but the code inside the if-statement is not executing.
Two questions:
What is wrong with this approach?
Is this the best approach when using StoryBoards? Can I pass data via viewWillDisappear?
Can I use segues to pass data back to the table view controller from the view controller?
It makes all the sense in the world to pass your data in the prepareForSegue:sender:. I would not recommend passing data in viewWillDisappear because it just makes it messy and it reduces readability + it becomes harder to keep track.
I think your string comparison is not working! Put an NSLog for your identifier string see on the console. I have a feeling it might not like the "ä" character in comparison.
About your last question, as Gabriel.Massana pointed out, for passing data back, using delegate is the way to go.
Note 1: Another problem I noticed is a possible typo you might have "apv" and "avc".
Note 2: Another reason for it failing is that you are setting the TextField before viewDidLoad gets called on your destination controller. I suggest that pass it as string and in the viewDidLoad of your destination, set the text to your TextField.
I have been trying to use PKRevealcontroller with storyboards but can't seem to find a way to integrate it. All I want is to have a main view controller and a menu on the left.
I can't seem to figure out how and where to add code. If someone has an example that would be great.
I want to try using PKRevealcontroller because it seems to be the only one that passes information from one view controller to another.
You don't have to use PKReveal if all you want to do is pass data between segues. The best and simplest way to do this would be to use the prepareForeSegue method. The method would look something like this:
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
FirstViewController *transferViewController = segue.destinationViewController;
NSLog(#"prepareForSegue: %#", segue.identifier);
if([segue.identifier isEqualToString:#"joeSegue"])
{
//the data you would pass goes here...
}
}
For a simple explanation, see this tutorial.
If you must use PKReveal, here is a tutorial on how it's done.
I want to pass a photo taken in the first view controller to a second view controller. I want the user to take the photo in the first view controller and then crop in in the second view controller and then save.. So its like.. User take photo→crop→save. I just want to do this simple task but taking me days to get the segue go right.. Is segue the best way to do this? or is there a more easier way to do this task. I am a beginner in objective -c so its making me confused with segues and all the stuff.
You need to implement prepareForSegue:sender: in the source view controller. This will give you access to the destinationViewController via the passed storyboard. Then you can set the image so its available when the destination view controller is displayed.
As far as segue is concerned you need to create a segue arrow using storyboard by dragging arrow from first view controller to second view controller, and most importantly you need to give the segue an identifier or name.
For firing you segue you may do it programatically, like:
[self performSegueWithIdentifier:#"ShowSecondScreen" sender:self];
For handling things when segue is fired you need to write prepareForSegue() method, you may pass any object from current viewController to next viewController:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([segue.identifier isEqualToString:#"ShowSecondScreen"])
{
SecondViewController *secondViewController = segue.destinationViewController;
secondViewController.imageObj = image;
}
}
Let's say I have a UILabel on ViewControllerA and and UITextField on ViewControllerB. I want to go to ViewControllerB and input text then press a button to go back to ViewControllerA. The UILabel should now read whatever was typed in the UITextField.
I was able to accomplish the above by using NSUserDefaults and also using delegation. I am using Storyboards to do this. My question is about the segues used in the storyboards.
It seems when using delegation I must go to and from the storyboard with code and not visually connect the view controllers with a segue in order for the data to transfer. Here is the code when I press a button on my ViewController A:
- (IBAction)pressFirstButton:(id)sender {
UIStoryboard* sb = [UIStoryboard storyboardWithName:#"MainStoryboard" bundle:nil];
RBViewController2 *vc2 = [sb instantiateViewControllerWithIdentifier:#"ViewController2"];
[vc2 setDelegate:self];
[self presentViewController:vc2 animated:YES completion:NULL];
}
when passing the data back from ViewControllerB to ViewControllerA I do this:
- (IBAction)buttonSegueBackTo1:(id)sender {
NSString *sendThis = self.textFieldVC2.text;
[self.delegate passTextFieldInput:sendThis];
[self dismissViewControllerAnimated:YES completion:NULL];
}
No segue has been drawn between the view controllers and everything works fine. If I don't write this same code, and draw in a segue, the data won't pass backwards. However when I try passing data like this using NSUserDefaults I don't have to write the code to go to and from the view controllers. Instead I can simply connect the view controllers with a drawn segue. The weird thing is, if I'm trying to pass the data in using NSUserDefaults when manually coding the view controllers (an not drawing the segue) the data doesn't transfer.
I'm thinking maybe instead of writing the code in the -(IBAction) pressFirstButton:(id) sender method, I should be putting the code in the prepareForSegue method.
My question is why do drawn segues sometime cause data to be lost? Must all delegation be done without drawn segues? If NSUserDefaults require segues to transfer properly and delegation require code to transfer properly then if I have a view that requires both, it seems that NSUserDefaults will trump the delegation b/c the manual segue being used "resets" the view and only the NSUserDefaults data remains.
Normal segues (any other than unwind segues) ALWAYS create new view controllers. So, if you're using anything other than an unwind segue to go back to A, you're really not "going back", you're creating a new ViewControllerA. Unwind segues aren't normally used in a case like you're presenting, just going back one controller, but you could.
This situation also isn't a good place to use user defaults. The Apple recommended way, is to use delegation, like you do in the code your question. The way you show, is probably the best way to do it, rather than using a segue to go back. You certainly could use a segue to go forward though, and in that case you would implement prepareForSegue: so you can set yourself as the delegate and/or pass any data forward.
Your question is a little dense to parse but I think you are asking if there is a way to get pass data through segues. The answer is yes, and much better than the workarounds you are trying.
In your button you would call:
[self performSegueWithIdentifier:#"scrollerSegue" sender:self];
This will trigger the method below and it is here that you can set the data on the destination viewController. You can set abstract properties on the destination viewController but you can't populate an UIKit elements (labels, imageViews, etc.) because they don't exist yet. Instead set properties and then in viewWillAppear in the destination viewController, do the set up as needed. (alternatively, instead of passing data, you could just set the delegate and then call methods on the delegate to get the data as needed).
For getting data back, using the delegate and calling methods on it seems to be the Apple recommended way of doing things.
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:#"scrollerSegue"])
{
ScrollViewController * target = segue.destinationViewController;
target.assetsArray = self.assetsArray;
target.delegate = self;
}
}
The kind of design that I'm trying to accomplish in my app currently consists of a navigation controller that is the root controller for another View controller known as Test. Test consists of a UITableView in the top half and an UIImageView in the bottom half. THe navigation bar on the top (which is there as a result of the navigation controller) contains two buttons. The image at the link below ( I don't have the reputation points to post an image directly) should make it very clear.
http://i.imgur.com/GM5eH.png?1
I want my design to be in such a way that depending on which button is pressed the image in the imageview is changed while, though the the text in the table view remains the same, they will transition to completely different screens going forward. To give an example, regardless of which button is tapped my table view will consist of : Option 1, Option 2 and Option 3. However, Option 1 for button A is different from Option B and so on.And, this is where the challenge is for me. I have been able to swap out the images based on the pressing of the button succefully. I did this by using an IBActionNavBarButonPressed and then swapping out the images based on the sender tag. Unfortunately, I don't know how to proceed from here. So for example I have my next couple of screens here. But, how do I set up the segues/transitions in such a way that only Option 1 of choice A goes to a certain screen and so on. From my understanding, I'm looking at a combination of prepareforSegue and the navBarbuttonPress IBAction but I'm still not sure how this would work.
Guys, I'm fairly certain as to what I'm trying to but since I'm new to objective C, I'm not completely sure of how to do it. Essentially, I want the logic to be something like, if(element.selected==0) && (IBActionProvider==1) { performSegueWithIdentifier:#"blah" sender.self]; My issue is whether to put this in the IBAction navBarButtonPressedMethod or to put it in the didSelectRowAtIndexPath method.
Thanks and sorry for the long question!
First you give names to other storyboards views. It contains left hand panel(Storyboard Identifier :).
You should create segue for all buttons and give identifier to it.
Then you should use prepareforSegue like this
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:#"ToContacts"])
{
// Get reference to the destination view controller
ContactVC *targetVC = [segue destinationViewController];
// Pass any objects to the view controller here, like...
targetVC.CompanyNme = selectedRowValue;
}
if ([[segue identifier] isEqualToString:#"ViewCompany"])
{
ContactVC *targetVC = [segue destinationViewController];
targetVC.CompanyNme = selectedRowValue;
}
}
#"ToContacts" means your storyboard identifier.