I know there are tons of questions out there about passing messages between different view controllers. I've checked them all but I can't get it working.
I've followed this tutorial: http://www.youtube.com/watch?v=XZWT0IV8FrI replacing the storyboard with a navigation controller but I run across the following issue over and over again: 'Cannot find protocol declaration for...'
Here is the code:
FirstViewController.h
#import "SecondViewController.h"
#interface FirstViewController : UIViewController <SecondViewControllerDelegate>{
//In this line above is where I get the error 'Cannot find protocol declaration for SecondViewControllerDelegate'
IBOutlet UITextField *userNameTextField;
}
#property (nonatomic, strong) UITextField *userNameTextField;
-(IBAction)goNext:(id)sender;
#end
FirstViewController.m
#import "FirstViewController.h"
#interface FirstViewController ()
#end
#implementation FirstViewController
#synthesize userNameTextField;
-(void)goNext:(id)sender{
SecondViewController *secondVC = [[SecondViewController alloc]init];
secondVC.delegate = self;
[self.navigationController pushViewController:secondVC animated:YES];
}
-(void)done:(NSString*)name{
NSLog(#"BACK in firstVC");
userNameTextField.text = name;
}
#end
SecondViewController.h
#import "FirstViewController.h"
#protocol SecondViewControllerDelegate <NSObject>
-(void)done:(NSString*)someText;
#end
#interface SecondViewController : UIViewController{
IBOutlet UITextField *someText;
IBOutlet UIButton *returnButton;
id delegate;
}
#property (assign, nonatomic) id <SecondViewControllerDelegate> delegate;
#property (strong, nonatomic) UITextField *someText;
-(IBAction)goBack:(id)sender;
#end
SecondViewController.m
#import "SecondViewController.h"
#interface SecondViewController ()
#end
#implementation SecondViewController
#synthesize someText;
#synthesize delegate = _delegate;
-(void)goBack:(id)sender{
[self.delegate done:someText.text];
FirstViewController *firstVC = [[FirstViewController alloc]init];
[self.navigationController pushViewController:firstVC animated:YES];
}
#end
In your SecondViewController goBack implementation you are creating a new FirstViewController rather than popping your navigation controller, code should read...
-(void)goBack:(id)sender{
[self.delegate done:someText.text];
[self.navigationController popViewControllerAnimated:YES];
}
And also in your SecondViewController.h remover this #import "FirstViewController.h" as it is no longer needed and could be confusing the compiler
Your protocol name is EYSSecondViewControllerDelegate:
#protocol EYSSecondViewControllerDelegate <NSObject>
but you call it SecondViewControllerDelegate in two places:
#interface EYSFirstViewController : UIViewController <SecondViewControllerDelegate>{...
#property (assign, nonatomic) id <SecondViewControllerDelegate> delegate;...
Make sure that the name match and it should works fine.
In SecondViewController.h
remove line id delegate;
In SecondViewController.m
Update code -> [delegate done:someText.text];
'self.' remove
Try it
Related
I have one view and one View Controller. I am trying to have a reference to View Controller from the view.
PlusCalendarView.h
#interface PlusCalendarView : TSQCalendarView
#property (nonatomic, strong) UIViewController *initialVC;
#end
ViewController.m
- (void)viewDidLoad {
[super viewDidLoad];
[self setUpCalendarView:self.myCalendarView];
self.myCalendarView.initialVC = self; // ERROR: Property initialVC not found on object of type "PlusCalendarView"
}
How come it cannot find initialVC property?
Update:
ViewController.h
#import <UIKit/UIKit.h>
#import <TimesSquare/TimesSquare.h>
#interface PlusCalendarView : TSQCalendarView;
#end
#interface ViewController : UIViewController
#property (nonatomic, strong) NSCalendar *calendar;
#property (strong, nonatomic) IBOutlet PlusCalendarView *myCalendarView;
#end
The problem is that you're declaring PlusCalendarView in ViewController.h AND PlusCalendarView.h. You should remove the #interface declaration from ViewController.h.
Instead, add #class PlusCalendarView in ViewController.h then #import "PlusCalendarView.h" in ViewController.m
I'm building my first iOS app to try and learn iOS coding. However, I need to pass a value xAuthToken from one controller to the other. I can't seem to get it working to. I init the value in the first controller ViewController, but then I need it in SettingsController. I keep getting errors and the one it throws now is: Property 'ViewController' not found on object of type 'ViewController'
What am I doing wrong?
ViewController.h
#import <UIKit/UIKit.h>
#import "SettingsController.h"
#interface ViewController : UIViewController <UITextFieldDelegate>
#property (weak, nonatomic) IBOutlet UITextField *txtUsername;
#property (weak, nonatomic) IBOutlet UITextField *txtPassword;
- (IBAction)sigininClicked:(id)sender;
- (IBAction)backgroundTap:(id)sender;
#end
ViewController.m
#import "ViewController.h"
#interface ViewController ()
#property (nonatomic) NSString *xAuthToken;
#end
#implementation ViewController
- (IBAction)sigininClicked:(id)sender {
NSString *xAuthToken = #"0";
self.viewController = [[SettingsController alloc] init];
self.viewController.xAuthToken = xAuthToken;
[self performSegueWithIdentifier:#"login_success" sender:self];
}
SettingsController.h
#import <Foundation/Foundation.h>
#interface SettingsController : UIViewController
#end
SettingsController.m
#interface SettingsController ()
#property (weak, nonatomic) IBOutlet UITextField *myTextField;
#property (weak, nonatomic) IBOutlet UISwitch *mySwitch;
#end
#implementation SettingsController
//THIS IS WHERE I NEED XAUTHTOKEN
If you have a segue that presents your SettingsController, pass the information it needs in prepareForSegue. Don't create a new local SettingsController.
You can do something like
viewController = [self.storyboard instantiateviewcontrollerwithidentifier:#"your vc name"];
viewController.Xauthtoken = data;
// Do something else with this.
Or another way ( I don't know if it's good or bad, use it while your vc is already active ):
Use NSNotificationCenter and pass values between it.
Third way is create delegate for first Viewcontroller.
Try this in your ViewController.m:
#import "ViewController.h"
#interface ViewController ()
#property (nonatomic) NSString *xAuthToken;
#end
#implementation ViewController
- (IBAction)sigininClicked:(id)sender {
xAuthToken = #"Your Value Here";
[self performSegueWithIdentifier:#"login_success" sender:self];
}
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if ([segue.identifier isEqualToString:#"login_success"]) {
SettingsController *destViewController = segue.destinationViewController;
destViewController.xAuthToken = xAuthToken;
}
}
And in your SettingsController.h
#import <Foundation/Foundation.h>
#interface SettingsController : UIViewController
#property (nonatomic,strong) NSString *xAuthToken;
#end
SettingsController.m
#interface SettingsController ()
#property (weak, nonatomic) IBOutlet UITextField *myTextField;
#property (weak, nonatomic) IBOutlet UISwitch *mySwitch;
#end
#implementation SettingsController
-(void)viewDidLoad{
NSLog("%#",xAuthToken);
}
I have been staring at code too long and know i am doing something silly here with my Protocols if someone could enlighten me that would be great.
Trying to get my areaNameLabel to change to cell.nameLabel.text across viewcontrollers.
FirstTableViewController.h
#import <UIKit/UIKit.h>
#import "FirstTableCell.h"
#import "SecondViewController.h"
#interface FirstTableViewController : UITableViewController <UITableViewDataSource, UITableViewDelegate, passNames>
#property (nonatomic, strong) NSString *passedNameString;
#property (strong, nonatomic) NSMutableArray *names;
FirstTableViewController.m
#import "FirstTableViewController.h"
#interface FirstTableViewController ()
#end
#implementation FirstTableViewController
#synthesize names;
#synthesize passedNameString;
- (void)viewDidLoad
{
[super viewDidLoad];
names = [NSMutableArray arrayWithObjects:#"Bondi", #"Miranda", nil];
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
FirstTableCell *cell = (FirstTableCell *)[tableView cellForRowAtIndexPath:indexPath];
if ([cell.nameLabel.text isEqualToString:#"Bondi"]) {
SecondViewController *mapController = [[SecondViewController alloc] init];
NSString *passedName = cell.nameLabel.text;
mapController.passedNameString = passedName;
[mapController setDelegate:self];
self.tabBarController.selectedIndex = 1;
NSLog(#"Hola");
}
[tableView deselectRowAtIndexPath:indexPath animated:YES];
}
#pragma mark - Protocol Methods
-(void)setAreaName:(NSString *)areaName {
passedNameString = areaName;
}
SecondViewController.h
#import <UIKit/UIKit.h>
#protocol passNames <NSObject>
-(void)setAreaName:(NSString *)areaName;
#end
#interface SecondViewController : UIViewController <RMMapViewDelegate>
#property (retain) id <passNames> delegate;
#property (nonatomic, strong) NSString *passedNameString;
#property (weak, nonatomic) IBOutlet RMMapView *mapView;
#property (weak, nonatomic) IBOutlet UILabel *areaNameLabel;
#end
SecondViewController.m
#import "SecondViewController.h"
#import "FirstTableViewController.h"
#interface SecondViewController ()
#end
#implementation SecondViewController #synthesize areaNameLabel; #synthesize delegate, passedNameString;
- (void)viewDidLoad {
[super viewDidLoad];
passedNameString = areaNameLabel.text;
[[self delegate] setAreaName:passedNameString];
if ([areaNameLabel.text isEqualToString:#"Bondi"]) {
NSLog(#"You got it!");
}
}
Any other critiques feel free to throw in - I've had a look at some other Protocol questions and examples but i know it is something obvious i am missing.
The problem is that your SecondViewController has no relationship to the passNames protocol (being declared in the same header does not count).
Since protocol methods need to be implemented (or their implementation be inherited from the base) and your SecondViewController does not do that, you cannot call setAreaName: without triggering an error.
If you would like to use a common protocol in two view controllers, you need to do this:
Give passNames protocol a more conventional name that starts in a capital letter, and put it in a separate header file
Include that header in both view controllers (the #import "SecondViewController.h" in the FirstTableViewController.h does not look right)
Put implementations of setAreaName: in both view controllers.
Note that you cannot put the common functionality in a superclass, because your view controllers inherit from different bases (i.e. UIViewController and UITableViewController).
So I have 3 views as follows: viewController >> viewController2 >> viewController3.
In viewController3 I have created a Delegate Protocol. The protocol method is a simple method that prints out an NSLog.
When I call the delegates from ViewController3, only its parent (viewController2 ) responds not the (first) viewController. There are no errors.I think problem has got something to do with [v2 setDelegate:self]; in the viewController.m file.
Nevertheless,[self.v3 setDelegate:self]; works fine in ViewController2.m file.
Why does the (first) viewController delegate not respond ? Do delegates only work with its immediate child ??
> **ViewController.h**
#import <UIKit/UIKit.h>
#import "ViewController2.h"
#import "ViewController2.h"
#interface ViewController : UIViewController <PassData>{
ViewController2 *v2;
}
#property (strong, nonatomic) ViewController2 *v2;
> Blockquote
- (IBAction)button:(id)sender;
#end
> **ViewController.M**
#import "ViewController.h"
#interface ViewController ()
#end
#implementation ViewController
#synthesize v2;
- (IBAction)button:(id)sender {
v2 = [[ViewController2 alloc]initWithNibName:#"ViewController2" bundle:nil];
[v2 setDelegate:self];
[self.view addSubview:v2.view];
}
-(void)print: (BOOL)success;{
if (success == YES) {
NSLog(#"ViewController called");
}
}
#end
> > ViewController2.h
#import <UIKit/UIKit.h>
#import "ViewController3.h"
#interface ViewController2 : UIViewController <PassData> {
ViewController3 *v3;
}
#property (strong, nonatomic)ViewController3 *v3;
#property (retain) id delegate;
- (IBAction)button:(id)sender;
#end
ViewController2.m
#import "ViewController2.h"
#interface ViewController2 ()
#end
#implementation ViewController2
#synthesize v3,delegate;
- (IBAction)button:(id)sender {
v3 = [[ViewController3 alloc]initWithNibName:#"ViewController3" bundle:nil];
[self.v3 setDelegate:self];
[self.view addSubview:v3.view];
}
-(void)print: (BOOL)success;{
if (success == YES) {
NSLog(#"ViewController2 called");
}
}
#end
> ViewController3.h
#import <UIKit/UIKit.h>
#protocol PassData <NSObject>
#required
-(void)print:(BOOL)success;
#end
#interface ViewController3 : UIViewController {
id<PassData> delegate;
}
#property (retain) id delegate;
- (IBAction)callButton:(id)sender;
#end
ViewController3.m
#import "ViewController3.h"
#interface ViewController3 ()
#end
#implementation ViewController3
#synthesize delegate;
- (IBAction)callButton:(id)sender {
// call all delegates
[[self delegate]print:YES];
}
#end
v2 doesn't have a method "print", that's a protocol method of v3 -- you can't chain delegate messages like this. If you want multiple controllers to respond to something in another controller, then you should use an NSNotification -- any number of objects can register to receive a notification.
I'm trying to access some things from another viewcontroller (iOS).
I have my ViewController.h:
#import <UIKit/UIKit.h>
#interface ViewController : UIViewController <UITextFieldDelegate> {
...
}
#end
ViewController.m:
#import "ViewController.h"
#import "ViewController2.h"
#interface ViewController ()
#end
#implementation ViewController
- (void)viewDidLoad
{
ViewController2.someVar = #"cakes"; // this is where I'm trying to set something in vc2
}
ViewController2.h:
#import <UIKit/UIKit.h>
#interface ViewController2 : UIViewController <UITableViewDataSource, UITableViewDelegate, UISearchDisplayDelegate>
{
...
}
#property (nonatomic, copy) NSString *someVar;
#end
ViewController2.m:
#import "ViewController2.h"
#interface ViewController2 ()
#end
#implementation ViewController2
#synthesize someVar;
etc.
But at the line where I try to access this var, it gives me the following error:
Property 'someVar' not found on object of type 'ViewController2'.
In what way would I achieve accessing this other view controller?
You have to create a ViewControlle2 object in your Viewcontroller.m.
ViewController2 *myVC2 = [[ViewController2 alloc] initWithNibName:#"ViewController2" bundle:nil];
myVC2.someVar = #"cakes";
Another way to do this is by using delegates. If you created ViewController1 in AppDelegate, you should also create ViewController2 in AppDelegate, or where ever you create your ViewControllers. Then you ViewController1 would send a message to AppDelegate to get the data from ViewController2 and vice versa. This makes ViewController1 and ViewController2 no longer dependent on each other.
So in AppDelegate.h we'd have something like this
#interface AppDelegate : NSObject <MyViewControllerDelegate>
#property (nonatomic) ViewController1 *viewController1;
#property (nonatomic) ViewController2 *viewController2;
#end
Then in both view controllers you can add this line in the .h
#property (nonatomic) id<MyViewControllerDelegate> delegate;
This just gives us a variable to use to refer to the delegate from within the ViewController's .m
You also need to create the MyViewControllerDelegate protocol, so in a file called MyViewControllerDelegate.h
#protocol MyViewControllerDelegate
- (ViewController1 *) viewController1;
- (ViewControlelr2 *) viewController2;
#end
Then when you create the ViewControllers in AppDelegate.m, you should also set AppDelegate as the ViewController's delegate.
self.viewController1 = [[ViewController1 alloc] init];
self.viewController1.delegate = self;
self.viewController2 = [[ViewController2 alloc] init];
self.viewController2.delegate = self;
So with all of this delegate set up done, you should be able to access viewController2.someVar from viewController1 through the delegate by using:
self.delegate.viewController2.someVar = #"Cakes";
Hope this isn't too long winded.