I am working on an app in Xcode, using modal segues to navigate forwards and using unwind segues to go back to the previous view and also to the home view. However, the segue is just not working when I open up the simulator, no errors are shown and I have used the same approach to unwind segue as is used in the Apple To-do list tutorial, so not sure why this isn't working.
Below is my .h file for one of the views I want to unwind from:
#import <UIKit/UIKit.h>
#interface XYZBonBonoftheDayViewController : UIViewController
#property (strong, nonatomic) IBOutlet UIWebView *BBoD;
- (IBAction)unwindBBoD:(UIStoryboardSegue *)segue;
#end
Here is my .m file from the same view:
#import "XYZBonBonoftheDayViewController.h"
#interface XYZBonBonoftheDayViewController ()
#end
#implementation XYZBonBonoftheDayViewController
- (IBAction)unwindBBoD:(UIStoryboardSegue *)segue
{
}
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad {
[super viewDidLoad];}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}
#end
If anyone could help, this would be immensely helpful! Thanks in advance :)
Related
So I'm trying to get a hang of using delegates, and I've watched a few tutorials on how to use them so far. I still find them confusing and after trying to implement one myself, have an issue that I can't seem to solve.
I have two ViewControllers, the first one ViewController contains a UITextField *sampleTextField and a button with the method switchViews. It also contains the protocol declaration with the method sendTextToViewController. SwitchViews is also linked to a segue that switches to the SecondViewController. In SecondViewController the only object is a UILabel *outputLabel When the user taps the button, it calls switchViews and the view changes to SecondViewController, and upon loading outputLabel should be changed to whatever text was entered in sampleTextField in ViewController. However the delegate method sendTextToViewController is never being called. All objects are created in Interface Builder.
Here is the code to make it a bit easier to understand:
ViewController.h
#import <UIKit/UIKit.h>
#protocol TextDelegate <NSObject>
-(void)sendTextToViewController:(NSString *)stringText;
#end
#interface ViewController : UIViewController
- (IBAction)switchViews:(id)sender;
#property (weak, nonatomic) IBOutlet UITextField *sampleTextField;
#property (weak, nonatomic) id<TextDelegate>delegate;
#end
Then declared this in ViewController.m
- (IBAction)switchViews:(id)sender {
NSLog(#"%#", self.sampleTextField.text);
[self.delegate sendTextToViewController:self.sampleTextField.text];
}
SecondViewController.h
#import <UIKit/UIKit.h>
#import "ViewController.h"
#interface SecondViewController : UIViewController <TextDelegate>
#property (weak, nonatomic) IBOutlet UILabel *outputLabel;
#end
SecondViewController.m
#import "SecondViewController.h"
#interface SecondViewController ()
#end
#implementation SecondViewController
#synthesize outputLabel;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
ViewController *vc = [[ViewController alloc]init];
[vc setDelegate:self];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
-(void)sendTextToViewController:(NSString *)stringText
{
NSLog(#"Sent text to vc");
[outputLabel setText:stringText];
}
I've looked at this and the first answer makes sense, but for some reason it's not working.
I do think that the problem is where I am setting calling [vc setDelegate:self], but not sure how to fix this. Some pointers in the right direction would be greatly appreciated. Keep in mind I'm new to obj-c so if you can explain what you are saying, that would be great. Thank you.
Your are creating a new instance of ViewController but you don't do anything with it.
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
ViewController *vc = [[ViewController alloc]init];
[vc setDelegate:self];
}
The SecondViewController needs to have reference to the FirstViewController to be able to set itself as a delegate.
First you don't have to use delegation to do such a program.
A simpler way would be just creating a property in the SecondViewController that you'll pass the content of the textField into it.
Your code doesn't work because you called sendTextToViewController on a delegate that hasn't been set. You have set the delegate to a new instance of ViewController, not the one presented onscreen.
I'm trying to implement simgle AdBanner instance for multiple views in an iOS app. For implementing AdbannerDelegate in a viewController one has to do
bannerview.delegate= self;
where bannerview is an instance of AdBannerView. This delegate method however has to be implemented in every viewController which amounts up to a lot of repeating code. How can I make up a simple class that implements all delegate methods and then I call use them in every viewController.
I think the viewControllers you are using are subclasses of UIViewController.
And you are saying all the viewControllers have the same delegate methods.
So,what i want to do is create new ViewController class (UIDelgateViewController) by SubClassing UIViewController and add all delegate methods there , and have all the other viewControllers subclass UIDelgateViewController.
The code goes like this,
.h file->
#interface UIDelegateViewController : UIViewController<ADBannerViewDelegate>
#property ADBannerView *bannerView;
#end
.m file ->
#import "UIDelegateViewController.h"
#interface UIDelegateViewController ()
#end
#implementation UIDelegateViewController
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
_bannerView = [[ADBannerView alloc] init];
_bannerView.delegate =self;
}
-(void)bannerDelegateMethod{
}
Now your Some viewController ->
#import "UIDelegateViewController.h"
#interface SomeViewController : UIDelegateViewController
#end
#import "SomeViewController.h"
#interface SomeViewController ()
#end
#implementation SomeViewController
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
[self.view addSubview:self.bannerView];
self.bannerView.frame = ..../
}
If you want to keep always on the screen the same banner while navigating and changing views, you should consider to use View Controller containtment API
A great example is that remarkable sample code written by Apple, that shows how to keep the same banner instance while moving in a tabbar or navigation controller. It could be also a great start for you project.
I'm trying to separate the UITextViewDelegate methods from the main class of my project, I created a class to manage the delegate methods, but I can not change the values of the IBOulets from the main class.
I made a test project with a ViewController and a TextFieldController, in the Storyboard I add a text field and a label. What I want to do is change the text of the label when I start to write in the text field. Here is the code:
ViewController.h:
#import <UIKit/UIKit.h>
#import "TextFieldController.h"
#interface ViewController : UIViewController
#property (strong, nonatomic) IBOutlet UITextField *textField;
#property (strong, nonatomic) IBOutlet UILabel *charactersLabel;
#end
ViewController.m:
#import "ViewController.h"
#interface ViewController ()
#property (nonatomic, strong) TextFieldController *textFieldController;
#end
#implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
_textFieldController = [[TextFieldController alloc] init];
_textField.delegate = _textFieldController;
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}
#end
TextFieldController.h:
#import <UIKit/UIKit.h>
#import "ViewController.h"
#interface TextFieldController : UIViewController <UITextFieldDelegate>
#end
Text Field Controller.m:
#import "TextFieldController.h"
#interface TextFieldController ()
#property ViewController *viewController;
#end
#implementation TextFieldController
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (BOOL) textFieldShouldBeginEditing:(UITextField *)textField {
NSLog(#"hello");
_viewController.charactersLabel.text = #"hello";
return YES;
}
#end
When I start writing in the text field the message "Hello" is printed in the log, but the text of the label does not change. I want to know how to change the label text value from the other class.
First change the TextFieldController.h like this:
#import <UIKit/UIKit.h>
#import "ViewController.h"
#interface TextFieldController : NSObject <UITextFieldDelegate>
{
}
#property (nonatomic, assign) ViewController *viewController;
#end
Then change your TextFieldController.m file like this:
#import "TextFieldController.h"
#interface TextFieldController ()
#end
#implementation TextFieldController
- (BOOL) textFieldShouldBeginEditing:(UITextField *)textField {
NSLog(#"hello");
self.viewController.charactersLabel.text = #"hello";
return YES;
}
#end
In the ViewController.m do like that:
#import "ViewController.h"
#interface ViewController ()
#property (nonatomic, strong) TextFieldController *textFieldController;
#end
#implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
_textFieldController = [[TextFieldController alloc] init];
_textFieldController.viewController = self;
_textField.delegate = _textFieldController;
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}
#end
This will work but I personally dont like that way you took.
Good luck :)
It's failing because _viewController is nil. You need to assign the viewController property in your delegate in order to support the two way communication.
Also, I'd strongly recommend you make your delegate object a subclass of NSObject, and not UIViewController. It does nothing with controlling views. You can just manually instantiate it in your ViewController objects viewDidLoad.
In TextViewController I don't see where the viewController property (_viewController ivar) is being set so it is probably nil. You should set it when you create the TextViewController instance.
When you are navigating to other controllers using storyboad's segue then you need to implement prepareForSegue method to initialised its properties as follows
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if([segue.identifier isEqualToString:#"segue for textFieldController"])
{
TextFieldController *_textFieldController = [segue destinationViewController];
_textField.delegate = _textFieldController;
}
}
But I was wondering, why are you setting textFieldDelegate here, why can't you set in TextFieldController's viewDidLoad method as then you didn't you to implement above prepareForSegue method call?
Besides you are keeping strong reference of each other and you are creating strong retain cycle.
One more thing, following code
_textField.delegate = _textFieldController;
will not work, until textFieldController is loaded and its viewDidLoad method is being called as you are only initialising it but its outlets will not be connected until view is loaded into navigation stack.
I am new at xcode and I am learning something new each day, I have gotten stuck. I want to create a custom button on a second Storyboard (MapTwoViewController), lets say it is a custom button that looks like a cloud and it goes from left to right.
I have created the custom button in the storyboard and I have created the IBOutlet in the GWSMapTwoViewController.h so it looks like this and is linked to the button:
#import <UIKit/UIKit.h>
#interface GWSMapTwoViewController : UIViewController
#property (nonatomic, strong) IBOutlet UIButton *cloudAnimate;
#end
So in my GWSMapTwoViewController.m in my view did load I have the following:
#import "GWSMapTwoViewController.h"
#interface GWSMapTwoViewController ()
#end
#implementation GWSMapTwoViewController
#synthesize cloudAnimate;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Move UIView
cloudAnimate.center = CGPointMake(200.0, 100.0);
[UIView animateWithDuration:2.0 animations:^{ cloudAnimate.center = CGPointMake(100.0, 200.0);}];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#end
It just doesn't want to animate, it just goes straight to the end point, if I remove the animation code then the cloud appears at 200, 100 but if I put the animate code in it just moves to 100, 200 or whatever coordinates i put in. It just doesn't animate so its either in the starting point or the end point.
Can anyone tell when what i am doing wrong?
Move your animation code in
- (void)viewDidAppear:(BOOL)animated
because viewDidLoad is called before the view is visible.
Don't forget to call super
I have two view controllers: BSViewController and BSotherViewController. BSViewController has a button on it that is segues to BSotherViewController. That part works fine and I can see the one VC and then the "other" VC when I run on the simulator. But I have an NSLog(#"other"); in BSotherViewController's -viewDidLoad which is not showing in the console. A similar NSLog(#"other"); in BSViewController's -viewDidLoad which is showing in the console. I suspect the problem is the lack of an IBAction but I cannot figure where it should go and how it should be linked in the storyboard.
BSViewController.h
#import <UIKit/UIKit.h>
#interface BSViewController : UIViewController
#property (nonatomic) NSInteger number;
#end
BSViewController.m
#import "BSViewController.h"
#interface BSViewController ()
#end
#implementation BSViewController
#synthesize number;
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
self.number = 25;
NSLog(#"number: %d", self.number);
}
#end
BSotherViewController.h
#import <UIKit/UIKit.h>
#interface BSotherViewController : UIViewController
#property (nonatomic) NSInteger anumber;
#end
BSotherViewController.m
#import "BSotherViewController.h"
#include "BSViewController.h"
#interface BSotherViewController ()
#end
#implementation BSotherViewController
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
NSLog(#"other number:");
[super viewDidLoad];
// Do any additional setup after loading the view.
BSViewController *view = [[BSViewController alloc] init];
self.anumber = view.number;
NSLog(#"other number: %d", self.anumber);
}
In the storyboard is the second view controller set up as a BSotherViewController? You can verify by hovering over the view controller icon in the storyboard.
If it's not, then click it and go to the identity controller and type it in.