I'm trying to make a MVC and I have a CustomViewController and a CustomView. I have all the properties set up so that when a CustomViewController is created the view attached to the controller automatically becomes a instance of CutsomView.
My question is, how do I set it up so that I have one CustomViewController and, lets say, 1 or 2 CustomViews that are assigned to the controller?
MainViewController adds the CustomViewController as a child view controller which then adds the view associated with CustomViewController. Now after this is done, is there a way to add a second CustomView with it being attached to the CustomViewController?
Inside my MainViewController:
Is this possible or do I just need to create a new CustomViewController for every CustomView I want?
The purpose of this is to have these views stacked on top of each other with different data without calling a segue. Kinda like the way the new Facebook Paper app stacks their views.
Make CustomView class as a Parent of CustomViewController :
e.g:-
- ParentViewController.h
#interface ParentViewController : UIViewController
// You can put all common method here
- (IBAction) SetNavigationTitle:(NSString *)title;
#end
- LoginViewController
#interface LoginViewController : ParentViewController // in place of NSObject
#end
#implementation LoginViewController
- (void)viewDidLoad
{
[self SetNavigationTitle:#"User"];
}
#end
Related
I want to segue back from ViewControllerTwo to ViewControllerOne. I created a button that is responsible for doing that, but my problem is that the button is part of custom UIView class that is added to ViewControllerTwo, the button is not a part of the main view of ViewControllerTwo.
So in the custom UIView class I have the method that reacts if the button is clicked...
-(void)buttonClicked{
[SecondViewController performSegueWithIdentifier: "ShowFirstViewController" sender:nil];
}
When I do this I get an error: "performSegueWithIdentifier not a method of class" which makes sense.
So how can I segue between two viewcontrollers where the button responsible for the segue is not actually part of either view controller and is in a different class.
I think you can have a delegate call back to your SecondViewController and implement the performSegueWithIdentifier in the delegate callback method in SecondViewController.
It goes like this:
Above your custom UIView class interface create a protocol like this
#protocol CustomViewDelegate <NSObject>
- (void)buttonDidTap;
#end
Then create a property in your interface
#property (nonatomic, weak) id <CustomViewDelegate> delegate;
In your custom UIView *.m add this
-(void)buttonClicked{
[self.delegate buttonDidTap];
}
Conform the protocol to your SecondViewController like this
#interface SecondViewController: UIViewController <CustomViewDelegate>
set the delegate in your viewDidLoadMethod like this
-(void)viewDidLoad{
[super viewDidLoad];
self.yourCustomView.delegate = self;
}
implement this method inside the view controller .m file
- (void)buttonDidTap{
[self.performSegueWithIdentifier: "ShowFirstViewController" sender:self];
}
I'm more of a swift guy i think this should work fine.
iOS 9.3, Xcode 7.3, ARC enabled
This is what I'd do to troubleshoot:
Step 1: Make sure that you have a proper storyboard identifier for the view controllers you wish to segue between. The views simply attach to the view controllers, custom or not.
To do this, go to "*.storyboard" show the Utilities (right pane) and navigate to the Identity Inspector. Make sure you have "ShowFirstViewController" entered in the Storyboard ID field.
I searched for answers like Get to UIViewController from UIView? and couple of other answers but was not successful.
My issue is that I have a button in UIView lets say class1 and when I click on that button I want to load another view class2 which is UIViewController, and as I don't get navigationController in class1 I am unable to load the class2 view.
Please help me with this.
Thanks,
In Advance.
In general UIViews should not contain any logic that triggers the flow of app. This is the job of UIViewControllers. It's just a way of making the design of your code better and more organized.
One way I often use is to use a delegate pattern in my custom UIViews. Here is s simple setup:
In your MyCustomView .h file:
#class MyCustomView;
#protocol MyCustomViewDelegate <NSObject>
#optional
- (void)myViewDidTapOnButton:(MyCustomView)myCustomView;
#end
#interface MyCustomView : UIView
#property (weak, nonatomic) id <MyCustomViewDelegate> delegate;
#end
In your MyCustomView .m file:
- (IBAction)didTapMyButton:(id)sender {
if ([self.delegate respondsToSelector:#selector(myViewDidTapOnButton:)]) {
[self.delegate myViewDidTapOnButton:self];
}
}
Then in your viewcontroller, which is presenting your view:
interface:
#interface MyViewController ()<MyCustomViewDelegate>
#property (weak, nonatomic) IBOutlet UIView *myCustomView;
and implementation:
- (void)viewDidLoad {
[super viewDidLoad];
self.myCustomView.delegate = self;
}
- (void)myViewDidTapOnButton:(MyCustomView)myCustomView {
... code for presenting viewcontroller ...
}
Note:
Even if you dont use the parameter myCustomView which is sent in this method, its a common pattern and good habit to always send the sender of the delegate as the first parameter.
This is also used a lot by Apple, e.g. in
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath;
Two cases :
If you are using storyboard then give your NavigationController a
storyboard id. And create an object of navigationController in your
custom UIView class.
If you have customized the app launching from AppDelegate create a
public property of your navigationController. From your UIView class create an object of appDelegate with [UIApplication sharedApplication].delegate. From this object access the navigationController property
When you have the navigationController object you can push your viewcontroller with:
[navigationController pushViewController:ViewController animated:YES];
First fill storyboard ID with "MyViewController", which is a String field that you can use to create a new ViewController based on that storyboard ViewController. And later access that view controller like this:
- (IBAction)buttonPressed:(id)sender{
MyCustomViewController *newvc = [self.storyboard instantiateViewControllerWithIdentifier:#"MyViewController"];
[self presentViewController:newvc animated:YES completion:nil];
}
When you click your button,you can do this:
YouViewController *yourViewController = [YouViewController new];
[self.view addSubView:yourViewController.view];
Hope to help you.
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!
I am relatively new to Xcode and have tried to find the answer by searching, without luck.
My app has 5 View Controllers, V1 through V5, which are embedded in one Tab Bar Controller. Each View Controller has a segue to one and the same Setup Menu View Controller. The Menu changes some labels on the View Controllers. I use a delegate to make sure that the View Controller that calls the Menu gets updated with the new settings when you leave the Menu. However, this allows me to modify only the labels on the View Controller that called the Menu Controller, not on the 4 other ones.
I work form a Story Board. Is there a simple way to set the UILabels on V2, V3, V4 and V5 from V1 (and vice versa), or even better, set the labels on V1 through V5 from the Menu View Controller (which is not embedded in the Tab Bar Controller)?
I have seen something that could help here, but this seems rather complicated for what I want. The label changes I need are quite simple and are all predefined. Is there a method that is called every time you switch tabs in a tabbed application? Similar to ViewDidLoad?
This sounds like a good time for NSNotificationCenter. You are going to have your MenuViewController generate a notification with the new data that should be updated in your other view controllers:
// User has updated Menu values
[[NSNotificationCenter defaultCenter] postNotificationName:#"MenuDataDidChangeStuffForLabels" object:self userInfo:#{#"newLabelValue" : labelText}];
In your V1, V2, etc. you can add subscribe to these notifications using this code in your viewDidLoad method:
- (void)viewDidLoad {
[super viewDidLoad];
// Subscribe to NSNotifications named "MenuDataDidChangeStuffForLabels"
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(updateLabelText) name:#"MenuDataDidChangeStuffForLabels" object:nil];
}
Any object that subscribes using that code will call the updateLabelText method anytime a notification with that name is posted by the MenuViewController. From that method you can get the new label value and assign it to your label.
- (void)updateLabelText:(NSNotification *)notification {
NSString *newText = notification.userInfo[#"newLabelValue"];
myLabel.text = newText;
}
What I would do is subclass the tab bar controller and set that as the delegate for the menu view controller. From there, you can get updated when the labels are supposed to change and then communicate with the 5 tabs and update the labels.
Alternatively, you could use NSNotifications to let all the 5 view controllers know when settings change.
Lastly, you could add the menu settings to a singleton and have all of the view controllers observe the various properties that can change.
The label changes I need are quite simple and are all predefined. Is there a method that is called every time you switch tabs in a tabbed application? Similar to ViewDidLoad?
Regarding this question, the methods you're looking for are viewWillAppear: and viewDidAppear.
Here is a very simple solution if your workflow is also simple. This method changes all the labels from the different ViewControllers directly from what you call the Menu ViewController.
Let's say you have the following situation :
The blue ViewController is of the FirstViewController class. The green ViewController is of the SecondViewController class. The labels on each of those are referenced by the properties firstVCLabel and secondVCLabel (on the appropriate class' header file). Both these ViewControllers have a "Modal" button which simply segues modally on touch up inside.
So when you clic on any of these two buttons, the orange ViewController (of ModalViewController class) is presented. This ViewController has two buttons, "Change Label" and "Back", which are linked to touch up inside IBActions called changeLabel: and back:.
Here is the code for the ModalViewController :
#import "ModalViewController.h"
#import "FirstViewController.h"
#import "SecondViewController.h"
#interface ModalViewController ()
#end
#implementation ModalViewController
// Action linked to the "Change Label" button
- (IBAction)changeLabel:(id)sender {
// Access the presenting ViewController, which is directly the TabBarController in this particular case
// The cast is simply to get rid of the warning
UITabBarController *tabBarController = (UITabBarController*)self.presentingViewController;
// Go through all the ViewControllers presented by the TabBarController
for (UIViewController *viewController in tabBarController.viewControllers) {
// You can handle each ViewController separately by looking at its class
if ([viewController isKindOfClass:[FirstViewController class]]) {
// Cast the ViewController to access its properties
FirstViewController *firstVC = (FirstViewController*)viewController;
// Update the label
firstVC.firstVCLabel.text = #"Updated first VC label from Modal";
} else if ([viewController isKindOfClass:[SecondViewController class]]) {
SecondViewController *secondVC = (SecondViewController*)viewController;
secondVC.secondVCLabel.text = #"Updated second VC label from Modal";
}
}
}
// Action linked to the "Back" button
- (IBAction)back:(id)sender {
[self.presentingViewController dismissViewControllerAnimated:YES completion:nil];
}
For the sake of completeness, here are FirstViewController.h :
#import <UIKit/UIKit.h>
#interface FirstViewController : UIViewController
#property (weak, nonatomic) IBOutlet UILabel *firstVCLabel;
#end
And SecondViewController.h :
#import <UIKit/UIKit.h>
#interface SecondViewController : UIViewController
#property (weak, nonatomic) IBOutlet UILabel *secondVCLabel;
#end
There is no relevant code in the implementation of these classes.
Thanks a lot guys, I am impressed by your quick responses. In this particular case, viewWillAppear does the trick:
- (void)viewWillAppear:(BOOL)animated
{ [self AdaptLabels];
NSLog(#"View will appear.");
}
Every time a new tab is chosen, it updates the labels in the new View, according to a global variable set by the Menu, just before they appear. Very quick and clean. Thanks to all of you!
I am trying to create a Master-Detail application with a UITableView controller as both the master and detail. What I need to do is pass 8 strings of data when a row is selected to the detail UITableViewController. What's the best way of accomplishing this? I plan to have the detail UITableViewController as static cells, not dynamic.
You can create a variable in the master view controller to access the detail view controller. Then, in the master view controller's viewDidLoad, you can set up this variable so from this point on, all calls to self.detailViewController in the master view controller will be sent to the detail view controller. Sample code:
In MasterViewController.h:
#class DetailViewController // do not use include here to avoid reference cycles, just identify DetailViewController as a class
#interface MasterViewController : UITableViewController
// in the interface, declare property to access detail view controller
#property (strong, nonatomic) DetailViewController *detailViewController;
#end
In MasterViewController.m:
#include "DetailViewController.h"
// in the implementation, synthesize
#interface DetailViewController : UITableViewController
#synthesize DetailViewController;
// when the view loads
- (void)viewDidLoad {
// call super method
[super viewDidLoad];
// if you used XCode's built-in Matser/Detail application, this will set detailViewController to the detail view controller
self.detailViewController = (ITLDetailViewController *)[[self.splitViewController.viewControllers lastObject] topViewController];
}
This way, when you're in the master view controller code, you can call self.detailViewController.someProperty or [self.detailViewController someMethod].