when i push viewcontroller in navigation controller, shows black screen - empty view - ios

i tried using storyboard instantiateViewControllerWithIdentifier and it was working fine but i needed delegate method so i added below code when opening
SecondViewController from FirstViewController,
SecondViewController *svc=[[SeconViewController alloc] init];
svc.delegate=self;
[self.navigationController pushViewController:svc animated:YES];
but it opens black screen.any sort help is really appreciated. Thank you.
secondViewController.h file
#protocol sendDataToAudioDelegate <NSObject>
-(void)sendData:(NSMutableArray *) data;
#end
#interface AudioSavedFilesViewController : UIViewController <UITableViewDataSource, UITableViewDelegate>
#property (strong, nonatomic) IBOutlet UITableView *fileTable;
#property (strong, nonatomic) NSMutableArray *selectedIndices;
#property (strong, nonatomic) AVAudioPlayer *audioplayer;
- (IBAction)selectedFiles:(id)sender;
#property (nonatomic,assign)id <sendDataToAudioDelegate> delegate;
#end

Here:
SecondViewController *svc= [self.storyboard instantiateViewControllerWithIdentifier #"identifier"];
svc.delegate=self;
You are trying to set SecondViewController's delegate property. But the error you are getting when doing so:
property delegate not found on object type 'UIViewController'
Suggest that your SecondViewController class does not have a property called delegate. Hence you need:
#interface SecondViewController
#property (nonatomic, assign) id delegate;
#end

The reason is because you're creating a completely new instance of SecondViewController and pushing it onto the navigationController. You're not using the storyboard scene at all, thus, all the UI elements you added and connected up won't work either. You'll need to revert to how you were doing it with instantiateViewControllerWithIdentifier
You can still use the delegate as you're doing so there like this:
SecondViewController *svc= [self.storyboard instantiateViewControllerWithIdentifier #"identifier"];
svc.delegate=self;
[self.navigationController pushViewController:svc animated:YES];
Edit
After reading your comments...
I think you haven't set the scene in your storyboard to use the SecondViewController.
So you need to replicate this:

Related

.delegate self unrecognized selector sent to instance

I've a TableViewController in which I'm saving the selected cells in an NSMUtableArray. After selecting these cells user clicks on a confirm button and in this button action I'm trying to pass that NSMUtableArray so that I can display it in another viewController tableView
#import <UIKit/UIKit.h>
#protocol SelectedDXDelegate;
#interface AddDXTableViewController : UITableViewController
#property (nonatomic, strong) NSMutableArray *favDXArray;
#property (strong, nonatomic) UISearchController *searchController;
#property (nonatomic, strong) DX *AddEditDX;
#property (weak) id<SelectedDXDelegate> delegate;
- (IBAction)confirmPressed:(id)sender;
#end
#protocol SelectedDXDelegate <NSObject>
#required
-(void)getSelectedDX:(NSMutableArray *)DXselected;
#end
So when confirm button is pressed
- (IBAction)confirmPressed:(id)sender {
[self.delegate getSelectedDX:selectedDX];
[self.navigationController popViewControllerAnimated:YES];
}
it gets me to the
-(void)getSelectedDX:(NSMutableArray *)DXselected
{
myDXSelected = DXselected;
}
But it crashes the app here at reloadData in
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
[self.DXTableView reloadData];
}
You seem to have mixed up which view controller should be the delegate and which is the delegator. Also, you are just allocating a new instance of the AddDXTableViewController and assigning this as the delegate. This won't work; you need to have the existing instance of your view controller set as the delegate.
From what I can tell from your question, it is actually an instance of DXViewController that is to be the delegate of AddDXTableViewController
Presumably in DXViewController you have some code something like:
AddDXViewController *newViewController = [self.storyboard instantiateViewControllerWithIdentifier:#"AddDXViewController"];
[self.navigationController pushViewController:newViewController animated:YES];
What you need to do is set your delegate at this point:
AddDXViewController *newViewController = [self.storyboard instantiateViewControllerWithIdentifier:#"AddDXViewController"];
newViewController.delegate = self;
[self.navigationController pushViewController:newViewController animated:YES];
Having said all of that, since you are using a storyboard, a delegate is probably an unnecessarily complicated way of achieving your requirement; You can use a segue to move between the first and second view controller and an unwind segue to return back to the first. You can then implement prepareForSegue in the second view controller and use that to provide the array back to the first view controller
You have to make the UIViewController added in storyboard to AddDXTableViewController type in the identity inspector tab in story board.
See here the image
Here you can see the class type is ViewController, click on the dropdown and select the type to AddDXTableViewController
then type cast the viewController to AddDXTableViewController. As per my guess the instantiateViewControllerWithIdentifier: returns UIViewController which does not have delegate may cause the crash
AddDXTableViewController *addDXTVC = (AddDXTableViewController *)[self.storyboard instantiateViewControllerWithIdentifier:#"DXViewController"];
addDXTVC.delegate = self;
Let me know If it works

Pushing view controller is not working properly in ios

I am passing textfield data between two view controllers. i have two view controllers Firstviewcontroller, Secondviewcontroller. i have embed them in navigation but when i click the button on first view controller, second view controller is not showing only black screen is showing.below is my code.
First view controller.h
#import <UIKit/UIKit.h>
#import "secondViewController.h"
#interface FirstViewController : UIViewController<SecondViewControllerDelegate>
#property(nonatomic) secondViewController *secondview;
- (IBAction)btnclick:(id)sender;
#property (strong, nonatomic) IBOutlet UITextField *textfield1;
#end
First view controller.m
- (IBAction)btnclick:(id)sender {
secondViewController *SecondViewController= [[secondViewController alloc]init];
SecondViewController.data=self.textfield1.text;
[self.navigationController pushViewController:SecondViewController animated:YES];
}
- (void)dataFromController:(NSString *)data
{
[self.textfield1 setText:[NSString stringWithFormat:#"%#",data]];
}
Seconviewcontroller.h
#protocol SecondViewControllerDelegate <NSObject>
#required
- (void)dataFromController:(NSString *)data;
#end
#interface secondViewController : UIViewController
#property (nonatomic, retain) NSString *data;
#property(nonatomic,weak)id<SecondViewControllerDelegate> _delegate;
#property (strong, nonatomic) IBOutlet UITextField *textfield2;
#end
Seconviewcontroller.m
- (void)viewDidLoad {
[super viewDidLoad];
self.textfield2.text=[NSString stringWithFormat:#"%#",_data];
// Do any additional setup after loading the view.
}
whats the reason ??
You have to either use storyboard and let it intanciate the view controller for you:
[self.storyboard instantiateViewControllerWithIdentifier:#"SecondViewController"]
Or you can use xib files and tell the view controller which one to load:
[[SecondViewController alloc] initWithNibName:#"SecondViewController" bundle:nil]
second view controller is not showing only black screen is showing
Typically, this means that the view controller has no view. Your code does not explain where secondViewController is expected to get its view from. Is there a secondViewController.xib? If there is, is it correctly configured with a view outlet? If not, what does this view controller do in order to get its view?
Note that you have done a very odd thing with capitalization: you have given your class a small letter (secondViewController), while your instance has a capital latter (SecondViewController). This is backwards and a big mistake, and you should correct it immediately. Perhaps the problem is just a capitalization problem; if you call your class secondViewController and your xib file SecondViewController, that is not a match and they won't find each other.
I see "IBOutlet" in your code, it means you created the user interface of secondviewcontroller on storyboard. I guess [[secondViewController alloc]init] does not get UI element from storyboard then the black screen is shown. You have to create instance of secondViewController by loading from storyboard file.
Basically:
you can get storyboard via storyboard file name
on storyboard, Secondviewcontroller has an storyboard id which is set in Identity Inspector and you can use it to get instance of Secondviewcontroller
You can refer this link for more detail
loading iOS viewcontroller from storyboard
Hope this can help!

Communicating between 2 ViewControllers in Tab Bar Controller Project

I'm using a Tab Bar Controller in my project where the FirstViewController has a Mapbox map view and the SecondViewController has buttons that when pressed add a tile layer to the map view. Here's what I've tried. It creates error ***Use of undeclared identifier '_mapView' in the SecondViewController.m
//FirstViewController.h
#import <UIKit/UIKit.h>
#import <MapBox/MapBox.h>
#import "SecondViewController.h"
#import "SecondViewController.m"
#interface FirstViewController : UIViewController
#property (strong, nonatomic) IBOutlet RMMapView *mapView;
#end
//SecondViewController.h
#import <UIKit/UIKit.h>
#import <MapBox/MapBox.h>
#import "FirstViewController.h"
#import "FirstViewController.m"
#interface SecondViewController : UIViewController
- (IBAction)stationingLayerButton:(id)sender;
#end
//SecondViewController.m
- (IBAction)stationingLayerButton:(id)sender {
RMMBTilesSource *stationingMap = [[RMMBTilesSource alloc] initWithTileSetURL:[NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:#"Stationing20" ofType:#"mbtiles"]]];
[_mapView addTileSource:stationingMap atIndex:2];
}
}
The map calls are correct because I've tested it on a project that only uses one view controller. Now that I'm trying it on a Tab Bar Controller I get this error.
My question is
1.how do I get mapView in the FirstViewController to respond to calls in the SecondViewController?
2.Can this be done? I've imported the class files thinking this would open communication between the two but I'm stuck with this error.
Using tabbar controller you can get array on all associated view controllers.
You can find more details here: UITabbarController - viewControllers property
For example :
In a tabbar, if we have two view controllers, let say VC1 and VC2, then we can have any of these reference by using below code snippet.
Accessing VC1 reference in VC2 class implementation (VC2.m):
VC1 *myVC1ref = (VC1 *)[self.tabBarController.viewControllers objectAtIndex:0];
Now we can use public properties and methods of VC1 class and it will give the same reference which tabbar has loaded.
Hope this helps.
You basically add view controller to UITabBarController. So, if you need to access a UIViewControler in a specific tab, you need to query the UITabBarController. The following answered SO question might help you
any code example of how access viewcontroller from uitabbarcontroller?
Once you get hold of the view controller, you can pass all the data you want.
Thanks to Mrunal and Naz Mir.
I added a UITabBarController Class file and assigned it to my TabBarController. I then NSLog the array description of view controllers of the TabBarController.
//TabBarController.h
#property (strong, nonatomic) NSArray *array;
//TabBarController.m
- (void)viewDidLoad
{
NSArray *array = self.viewControllers;
NSLog(#"View Controllers = %#", [array description]);
}
I then imported the FirstViewController.h to SecondViewController.h and in SecondViewController.m I wrote...
//SecondViewController.m
- (IBAction)stationingLayerButton:(id)sender {
FirstViewController *FVC = [self.tabBarController.viewControllers objectAtIndex:0];
[[FVC mapView] addTileSource:stationingMap atIndex:2];
}

Implement custom UITabBar to multiple UIViewController's

I am trying to include a tab bar, with 4-5 tab bar items on it, to multiple view controllers of my app and will work as menu to jump between views (Map, About, Favourites etc.).
I have created on Storyboard a UITabBar item and set its Bar item's tags. Because the same tab bar will be used on several other view controllers (Main, View2, View3 etc.) I've decided to create a class that extends UITabBar. This will help me to customise the bar later. The UITabBar object in Storyboard is now an object of this class (BottomTabBar).
My question is, how I can detect when a bar item has been tapped?
In addition, because I am not familiar with TabBar, if you have any general guides or tips that will help me during development please share them with me.
BottomTabBar.h
#import <UIKit/UIKit.h>
#interface BottomTabBar : UITabBar <UITabBarDelegate>
#end
BottomTabBar.m
#import "BottomTabBar.h"
#implementation BottomTabBar
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
self.delegate = self;
}
return self;
}
- (void) tabBar:(UITabBar *)tabBar didSelectItem:(UITabBarItem *)item{
NSLog(#"Tabbed!");
}
#end
MainViewController.h
#import <UIKit/UIKit.h>
#import "BottomTabBar.h"
#interface MainViewController : UIViewController <UITableViewDataSource, UITableViewDelegate>{
AppDelegate *appDelegate;
NSArray *searchResults;
}
#property (strong, nonatomic) IBOutlet UIScrollView *slideshow;
#property (strong, nonatomic) IBOutlet UIPageControl *scroll;
#property (strong, nonatomic) IBOutlet BottomTabBar *bottomBar;
#end
This guide is really good:
http://www.rumex.it/2010/07/how-to-customise-the-tab-bar-uitabbar-in-an-iphone-application-part-1-of-2/
Notice there is also a second part there.
See this tutorials and source codes for custom tab bar.
Custom tabbar
I hope it helps you.

How to create generic view with viewcontroller for iOS5?

I'd like to develop for iOS5 and have a storyboard...
I've just created UIView with UIViewController on the storyboard.
I have added a lot of other UIButtons and labels and creates outlets to VC.
I would like to use this view with it's viewcontroller 3 times on a single parent view.
How is it possible? I dont want to copy "a lot of other UIButtons and labels" ...
Maybe i should create this view out of storyboard in separate XIB? How will i use XIB in storyboard?
UPDATE:
Thanx you, Juzzz - your solution works perfect:
You have to create 2 custom viewControllers (one for each view in your story board.
example:
#interface GraphCollectionViewController : UIViewController
#interface GraphViewController : UIViewController
To connect them you can use something called: UIViewController containment
For your GraphCollectionViewController create 3 outlets for your UIViews. Then create 3 properties of GraphViewController's (or an array, what you want) and initialize them in the view did load.
#property (strong, nonatomic) IBOutlet UIView *topView;
#property (strong, nonatomic) IBOutlet UIView *middleView;
#property (strong, nonatomic) IBOutlet UIView *bottomView;
#property (strong, nonatomic) GraphViewController *topGraphViewController;
#property (strong, nonatomic) GraphViewController *middleGraphViewController;
#property (strong, nonatomic) GraphViewController *bottomGraphViewController;
...
//top graph
self.topGraphViewController = [storyboard instantiateViewControllerWithIdentifier:#"GraphViewController"]; //init with view from storyboard
self.topGraphViewController.view.frame = self.topView.bounds; //set frame the same
[self.view addSubview:self.topGraphViewController.view];
[self addChildViewController:self.topGraphViewController];
[self.topGraphViewController didMoveToParentViewController:self];
//middle graph
self.middleGraphViewController = [storyboard instantiateViewControllerWithIdentifier:#"GraphViewController"]; //init with view from storyboard
self.middleGraphViewController.view.frame = self.middleView.bounds; //set frame the same
[self.view addSubview:self.middleGraphViewController.view];
[self addChildViewController:self.middleGraphViewController];
[self.middleGraphViewController didMoveToParentViewController:self];
//bottom graph
self.bottomGraphViewController = [storyboard instantiateViewControllerWithIdentifier:#"GraphViewController"]; //init with view from storyboard
self.bottomGraphViewController.view.frame = self.bottomView.bounds; //set frame the same
[self.view addSubview:self.bottomGraphViewController.view];
[self addChildViewController:self.bottomGraphViewController];
[self.bottomGraphViewController didMoveToParentViewController:self];
I think you get the point. For more understanding this example .
You can create a new view class (with it's own .h, .m files) and base this on the ViewController you created yourself.
So as for code:
#interface ViewController : UIViewController
Let's say the above is your original ViewController that you want to use in other places.
This has buttons, labels, etc. in it.
When you create a new view class base it on your own instead of UIViewController class like this:
#interface MyNewController : ViewController
Now that MyNewController is based on ViewController you created earlier, it should have it's buttons, labels, etc. you created as well.
Edit: You might also have to change your view's base class in the storyboard.
Click on the view you want to change, look at the right hand side attributes window, under Custom Class choose your own controller, in this case ViewController.

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