I have my first viewController "SFCrearMomentoViewController" and the second view is a tableViewController "MasterViewController". I need to select a row didSelectRowAtIndexPath and call the method didCelected which is implemented in my "first viewController" and close the view using dismissViewControllerAnimated.
The problem is that the method didCelected is never called. I've already tested this code in a test project using "two viewControllers" and it works but I don't know what's the problem in my current project.
SFCrearMomentoViewController.h
...
#import "MasterViewController.h"
#interface SFCrearMomentoViewController : UIViewController <UIImagePickerControllerDelegate, UINavigationControllerDelegate, UITextViewDelegate, MasterViewControllerDelegate>{
UIImagePickerController *picker;
}
...
SFCrearMomentoViewController.m
...
-(void)didSelected:(NSString *)nombre{
NSLog(#"didSelected method %#", nombre);
}
#end
MasterViewController.h
#import <UIKit/UIKit.h>
#protocol MasterViewControllerDelegate <NSObject>
#required
-(void) didSelected:(NSString *)nombre;
#end
#interface MasterViewController : UITableViewController
#property (weak, nonatomic) id <MasterViewControllerDelegate> delegate;
#end
MasterViewController.m
...
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
[self.delegate didSelected:#"row selected"];
[self dismissViewControllerAnimated:YES completion:nil];
}
...
Solution: I had to set the delegate self. I implemented it in the Segue.
-(void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
if ([segue.destinationViewController isKindOfClass:[MasterViewController class]]) {
MasterViewController *nextView = segue.destinationViewController;
nextView.delegate = self;
}
}
I had the same problem a few hours ago. In my case I set the delegate in prepareForSegue to the segue.destinationViewController but my destination view controller wasn't the View Controller with the delegate, it was a UINavigationController.
So I used this one:
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([segue.identifier isEqualToString:#"modalNeuerRaum"])
{
[(MyCustomModalViewController*)[(UINavigationController*)segue.destinationViewController viewControllers][0] setDelegate:self];
}
}
That worked for me, but I don't know if you have a UINavigationController..
You need to set the delegate in SFCrearMomentoViewController, you can do it in viewDidLoad, for example.
masterViewController.delegate = self;
I assume that you allocated and initialised new masterViewController object of MasterViewController type.
Related
I'm still learning objective-c and having a difficult time dismissing presented VCs from presenting VCs.
I read that to achieve this, you establish delegates to send the right messages back to the presenting VC from the presented VC.
My storyboard looks like so:
The issue I have is if I click UIBUtton2, it doesn't go back to Main VC. In fact, it does nothing.
However, clicking on any cells from VC1 segue to VC2 and clicking on UIButton3 transition back to VC1 as achieved.
MainVC.h:
#import "VC1.h"
#interface MainVC : UIViewController <VC1Delegate>
....
MainVC.m:
- (void)didGoBackToMainVC
{
[self dismissViewControllerAnimated:YES completion:nil];
}
....
VC1 .h:
#import "VC2.h"
#protocol VC1Delegate <NSObject>
#required
- (void)didGoBackToMainVC;
#end
#interface VC1 : UIViewController <UITableViewDataSource, UITableViewDelegate,
VC2Delegate>
#property (weak, nonatomic) id <VC1Delegate> delegate;
- (IBAction)UIButton2:(UIButton *)sender;
VC1.m:
- (void)didGoBackToVC1
{
[self dismissViewControllerAnimated:YES completion:nil];
}
- (IBAction)UIButton2:(UIButton *)sender
{
[self.delegate didGoBackToMainVC];
}
VC2.h:
#protocol VC2Delegate <NSObject>
#required
- (void)didGoBackToVC1;
#end
#interface VC2 : UIViewController
#property (weak, nonatomic) id <VC2Delegate> delegate;
- (IBAction)UIButton3:(UIButton *)sender;
VC2.m:
- (IBAction)UIButton3:(UIButton *)sender
{
[self.delegate didGoBackToSponsors];
}
I'm sure I'm not understanding this relationship properly. Can someone tell me what I'm doing wrong?
Thanks
From what I understand in your comments above I saw that your Main VC shows VC1 Modally correctly.
So I guess you have this code in your VC1.m
- (IBAction)goToMainVC:(id)sender
{
[self dismissViewControllerAnimated:YES completion:nil];
}
Next make sure your Cell in VC1 has 'Triggered Seques' Selection type of 'Show'. And you probably had this code in your VC1.m
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([segue.identifier isEqualToString:#"pushVC2"]) {
VC2 *vc2 = (VC2 *)segue.destinationViewController;
}
}
Next in your VC2.m you also should have this
- (IBAction)dismissVC2:(id)sender
{
[self dismissViewControllerAnimated:YES completion:nil];
}
If these are all you have, it should work like a charm. And no Delegates needed in this case. Hope this helps.
I tried many custom delegate examples in my code to send data from view B back to parent view A. Why am I getting NULL? There should be something I am missing. Please help. How can I call setupDate to receive (NSDate *)setAlarmDate in Parent view?
Parent view
#import "SetupViewController.h"
#interface ViewController : UIViewController <SetupViewControllerDelegate> {
NSTimer *timer;
}
#end
#import "ViewController.h"
#interface ViewController ()
#end
#implementation ViewController
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
if ([[segue identifier] isEqualToString:#"setupview"]) {
NSLog(#"prepare for segue");
SetupViewController *svc = [[SetupViewController alloc] init];
svc.delegate = self;
-(void)setupDate:(NSDate *)setAlarmDate{
NSLog(#"Hey Hey");
NSLog(#"%#", setAlarmDate);
}
#end
View B
#protocol SetupViewControllerDelegate <NSObject>
#required
-(void)setupDate:(NSDate *)setAlarmDate;
#end
#interface SetupViewController : UIViewController
#property (nonatomic, strong) id <SetupViewControllerDelegate> delegate;
//IB
#property (weak, nonatomic) IBOutlet UIDatePicker *pDatePicker;
#end
.m
#import "SetupViewController.h"
#import "ViewController.h"
#implementation SetupViewController
-(void)viewWillDisappear:(BOOL)animated{
NSDate *date = [self.pDatePicker date];
[[self delegate] setupDate:date];
}
#end
You should access the UIViewController using the segue's destinationViewController property instead of allocating an instance of your own, which is why your alarmDate = NULL.
E.g.
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:#"setupview"])
{
NSLog(#"prepare for segue");
SetupViewController *svc = [segue destinationViewController];
svc.delegate = self;
}
}
Also, as #Neru mentioned your delegate should be qualified as weak and not strong. The reason for this is because you will cause a retain cycle if you do not explicitly set the delegate = nil in the dealloc method.
I have a ViewController1 with a UILabel that can present a ViewController2 with a Modal Segue. I have a UITextField in ViewController2 that I need to access from ViewController1 so I can set my UILabel with the collected text.
I've tried working with the prepareForSegue without success. What should I do?
EDIT:
I'm using a Delegate, but I'm doing something wrong. Here's the code I'm using in ViewController2.h:
#class ViewController2;
#protocol VCProtocol
-(void)setName:(NSString *)name;
#end
#interface ViewController2 : UIViewController
#property (nonatomic, weak) id<VCProtocol> delegate;
#property (strong, nonatomic) IBOutlet UITextField *nameField;
- (IBAction)setButton:(id)sender
#end
ViewController2.m
-(IBAction)setButton:(id)sender
{
[self.delegate setName:nameField.text];
}
I conform to VCProtocol in my ViewController1.h. Then, in my ViewController1.m, I have this code:
- (void)setName:(NSString *)name
{
self.firstSignatureNameLabel.text = name;
}
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([segue.identifier isEqual:#"Sign"])
{
ViewController2 *VC = [segue destinationViewController];
VC.delegate = self;
}
}
You can create a protocol and set VC1 as delegate of VC2, and using prepareForSegue to set VC1 as VC2's delegate should work. I know that you said it didn't work, but I can't see why. Have a try with this :
Give an identifier to your segue (on storyboard), and implement prepareForSegue as shown below :
VC2Delegate.h :
#protocol VC2Delegate
- (void)updateLabel:(NSString *)text;
#end
VC1.h :
#import "VC2Delegate.h"
#interface VC1 : UIViewController <VC2Delegate>
// All your stuff
#end
VC1.m :
- (void)updateLabel:(NSString *)text {
[_label setText:text];
}
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if ([[segue identifier] isEqualToString:#"YourSegueIdentifier"]) {
VC2 * vc = [segue destinationViewController];
[vc2 setDelegate:self];
}
}
VC2.h :
#import "VC2Delegate.h"
#interface VC2 : UIViewController
#property (weak, nonatomic) id<VC2Delegate>delegate;
#end
VC2.m
- (void)textWasUpdated { // or whatever method where you detect the text has been changed
if (_delegate)
[_delegate updateLabel:[_textView text]];
}
Tell me if it works. Else, is prepareForSegue even been called ?
EDIT : Updated my answer (wasn't exactly what you needed).
But as you say it doesn't work :
Is prepareForSegue called ?
If so, is the delegate method called ?
If the delegate method isn't called, check that delegate is not nil.
You might want to remove the segue, and present it modally by yourself, using presentViewController:animated:completion:, like that :
- (IBAction)buttonWasTapped {
static NSString * const idModalView = #"modalView";
static NSString * const storyBoardName = #"MainStoryBoard"
UIStoryboard * storyboard = [UIStoryboard storyboardWithName:storyBoardName bundle:nil];
VC2 * vc = [storyboard instantiateViewControllerWithIdentifier:idModalView];
[vc setDelegate:self];
[self.navigationController presentViewController:vc2 animated:YES completion:nil];
}
When I ran into this problem, I chose the singleton approach and it works.
I have two view controllers. MainViewController pushes SignUp ViewController. Once SignUp View Controller dismisses, I need access to the same instance of MainViewController to update a UIButton.title.
.h MainView
//MainViewController.h
#import <UIKit/UIKit.h>
#interface MainViewController : UITableViewController
-(void)loggedIn;
#end
.m
#interface MainViewController ()
#end
-(void)loggedIn
{
NSLog (#"This is Logged in inside MainView.m");
self.logInOutButton.title = #"Logout";
}
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
UIViewController *destinationViewController = segue.destinationViewController;
Signup *signUp = [destinationViewController isKindOfClass:[SignUp class]] ? (Signup*)destinationViewController : nil;
signUp.mainViewController = self;
NSLog(#"Preapre For Segue %#", self);
}
.h SignUp
#import <UIKit/UIKit.h>
#import "MainViewController.h"
#interface SignUp : UIViewController
#property (strong, nonatomic) MainViewController *mainViewController;
#end
.m
#synthesize mainViewController;
- (void) loggedIn
{
NSLog(#" MainViewController %#", mainViewController);
[mainViewController loggedIn];
self.presentingViewController dismissViewControllerAnimated:YES completion:nil];
}
When I do NSLog I'm getting different values:
Preapre For Seg <STMainViewController: 0x9f7d600>
MainViewController (null)
Create a protocol / delegate. There are numerous resources on how to achieve this. In summary, you create the protocol on the destination viewController with the method you wish to run on the source and then you subscribe to that delegate from the source viewController.
Protocol Delegate
Dont forget to set the delegate from your prepareForSegue method
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
Signup *signUp = segue.destinationViewController;
signup.delegate = self;
NSLog(#"Preapre For Segue %#", self);
}
I have a HomeViewController which has a tableView populated with the array tableViewArray (originally empty). When I tap on a barButton, I segue modally to another View Controller called OutsideViewController which has another tableView populated by a different array.
What I would like to do is the following:
When I tap on a row in my OutsideViewController, I would like to add the selected string value to the tableViewArray so that when I go back to HomeViewController, the tableView has that new item listed in the tableView.
So far, this is what I have tried:
In the -didSelectRowAtIndexPath method of my OutsideViewController.m I have this piece of code:
NSString *selectedRow = [outsideArray objectAtIndex:indexPath.row];
NSMutableArray *temporaryArray = [NSMutableArray arrayWithObject:selectedRow];
HomeViewController *homeVC = [[HomeViewController alloc] init];
homeVC.tableViewArray = temporaryArray;
That code works but the tableView in HomeViewController is still empty when I return. Do I have to reload the tableView data?
Am I doing this right?
This is how I have set up my View Controllers in Storyboard:
HomeViewController -(modal segue)-> Navigation Controller --> OutsideViewController
Also, the return from OutsideViewController to HomeViewController is done by this line of code:
[self dismissViewControllerAnimated:YES completion:^{ }];
What you're doing wrong is you're allocationg a new HomeViewController. What I would do is keeep a reference to your HomeViewController in your OutsideViewController. Here is how.
First, in OutsideViewController.h, create a property, like this :
#property (nonatomic, weak) HomeViewController *homeVC;
Don't forget to add #class HomeViewController; in your .h, and #import "HomeViewController.h" in your .m
In HomeViewController, implement the prepareForSegue: method like this (replace ModalSegueIdentifier with your segue's identifier) :
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if ([segue.identifier isEqualToString:#"ModalSegueIdentifier"]) {
OutsideViewController *modalVC = (OutsideViewController*)segue.destinationViewController;
modalVC.homeVC = self;
}
}
Then, in OutsideViewController.m, instead of doing :
HomeViewController *homeVC = [[HomeViewController alloc] init];
homeVC.tableViewArray = temporaryArray;
Do this :
_homeVC.tableViewArray = temporaryArray;
When you leave your modal VC, your HomeVC will have the correct array. Don't forget to refresh your UITableView !
NB: Of course, there are many other ways, and it's maybe not the best one. But still, it should work.
You can achieve this too using delegation. You have to create a protocol in your OutsideViewController with a method that is responsible for sending the new object to your HomeViewController. Do this in OutsideViewController.h:
#protocol OutsideViewDelegate <NSObject>
- (void)OutsideViewController:(OutsideViewController *)controller didAddObject:(NSString *)object;
#end
In the implementation file you have to change a little bit the didSelectRowAtIndexPath: method:
NSString *selectedRow = [outsideArray objectAtIndex:indexPath.row];
[self.delegate OutsideViewController:self didAddObject:selectedRow];
In your HomeViewController.h you have to make your class conforms to the protocol:
#interface HomeViewController : UIViewController <OutsideViewDelegate>
After, create a property for the delegate:
#property (nonatomic, weak) id <OutsideViewDelegate> delegate;
To finish the process, implement the protocol in your HomeViewController.m to receive the new object from the OutsideViewController:
- (void)OutsideViewController:(OutsideViewController *)controller didAddObject:(NSString *)object
{
if (object != nil)
{
[self.tableViewArray addObject:object];
}
[self dismissViewControllerAnimated:YES completion:nil];
}
The code above depends of if your tableViewArray object is mutable or not. If it's not, you can change the type of the object argument in the protocol method to an inmutable array object and just assign tableViewArray to the new array.
EDIT:
In the prepareForSegue: method don't forget to set the delegate:
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:#"SEGUE_IDENTIFIER"]) {
OutsideViewController *outsideVC = (OutsideViewController *)[segue destinationViewController];
[outsideVC setDelegate:self];
}
}
First of all make sure you alloc, init your tableViewArray in HomeViewController
Second , In this line
HomeViewController *homeVC = [[HomeViewController alloc] init]
you are creating a new reference to your HomeViewController which is not correct, you need to pass correct reference, possibly creating HomeViewController variable in your OutsideViewController
Even though you correctly do first and second suggestion you will still see an empty tableview because you dont reload the tableview, somehow you need to fire [self.tableview reloadData]; method.
That means; you need to learn Delegate or NSNotifications pattern to communicate between child->parent scenarios
How do I set up a simple delegate to communicate between two view controllers?
http://mobile.tutsplus.com/tutorials/iphone/ios-sdk_nsnotificationcenter/
For your question just create a delegate in your Outside;
in your OutsideViewController.h
#import <UIKit/UIKit.h>
#protocol OutsideDelegate;
#interface{}//bunch of interface stuff
// Declare a property for the delegate
#property (weak) id <OutsideDelegate> delegate;
#end
// Protocol Header
#protocol OutsideDelegate <NSObject>
#optional
- (void)dismissPop:(NSMutableArray *)list;
#end
in your OutsideViewController.m
#synthesize delegate;
//run delegate method
[delegate dismissPop:temporaryArray];
[self dismissViewControllerAnimated:YES completion:^{ }];
in your HomeViewController.h
#import "OutsideViewController.h"
#interface OutsideViewController : UITableViewController<OutsideDelegate>
{}
#property (strong, nonatomic) OutsideViewController *pvc;
in your HomeViewController.m
#synthesize pvc;
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if ([[segue identifier] isEqualToString:#"your segue"]) {
pvc = [segue destinationViewController];
[pvc setDelegate:self];
}
}
// delegate callback function
- (void)dismissPop:(NSMutableArray *)list {
self.tableViewArray=list;
[self.tableView reloadData];
}
Another Solution Would be
Change your view stack to this:
Navigation Controller --> HomeViewController -(push segue)--> OutsideViewController
and apply rdurand's answer
and add this to your HomeViewController :
-(void)viewDidAppear:(BOOL)animated
{
[self.tableview reloadData];
}
In this solution since you are just push-pop viewcontrollers in a nabigation stack viewDidAppear will be called in HomeViewController everytime when you pop OutsideViewController.