I have a UIButton in my MainWindow.xib
When I tap the button, I want to swap the view. How do I do that?
I also want to transfer some data between the views (such as color preference and a string)
ANy sample code OR links to where I can find my answer would be very helpful.
alloc a temporary view controller, and call initWithNibName:. Then call [self presentModalViewController:(the view controller you just made) animated:YES]; (or NO). To pass data, create a method on your other view controller, add it to its .h file, and then in your .m file for the first view controller, import it and make it a class, and call [theviewcontrollermadeearlier yourmethod:argument :argument etc.]; e.g.:
MyFirstViewController.h:
#import <UIKit/UIKit.h>
#import "MySecondViewController.h"
...
#class MySecondViewController
...
MyFirstViewController.m:
...
MySecondViewController *tempVC = [[MySecondViewController alloc] initWithNibName:#"MySecondView"];
[self presentModalViewController:tempVC animated:YES];
[tempVC passDataWithString:#"a string" andColor:yellowcolor];
MySecondViewController.h:
#interface MySecondViewController : UIViewController {
...
}
- (void)passDataWithString:(NSString *)passedString andColor:(UIColor *)passedColor;
MySecondViewController.m:
...
- (void)passDataWithString:(NSString *)passedString andColor:(UIColor *)passedColor {
// Do something
}
EDIT:
To make the button trigger this, in your first view controller's header file, add IBOutlet IBAction *buttonPressed; in the #interface section, and then between } and #end add - (IBAction)buttonPressed;
Go into Interface Builder, and connect the IBAction to the button.
Then, in your first view controller's main file, add this:
- (IBAction)buttonPressed {
// The code to execute when pressed
}
Related
I seem to be unable to understand how to go about this. I have a button on my main view. This view contains a container view. I would like the button on the main view to make the container view segue to another view. I have set up an identifier for the segue, which goes from containerView1 to containerView2. This is a push-segue. The identifier is pushSegue.
On the button on the main view I have tried this:
- (IBAction)btnChangeLocation:(UIButton *)sender {
UIViewController *a = [[ContainerView1 alloc]init];
[a performSegueWithIdentifier:#"pushSegue" sender:nil];
}
I have successfully performed this segue from within containerView1, by just placing within it, and performing the segue from there. It works just fine then.
- (IBAction)testButton:(UIButton *)sender {
[self performSegueWithIdentifier:#"pushSegue" sender:nil];
}
But how would I go if I wanted to trigger the segue on the containerView1, from the button on the main view?
Thanks.
EDIT:
I would also like to be able to perform the same segue, from a container view, that is within the container view.
Just to summarize.
MainView----->ContainerView1-->pushSegue--->ContainerView2
ContaainerView1 has a subContainerView, which also has a button, which causes ContainerView1 to segue into ContainerView2. This button and the button on the MainView does the same thing really, just from different "locations".
EDIT: Added a picture to help explain. http://tinypic.com/r/maxpp2/8
With UIViewController *a = [[ContainerView1 alloc]init]; you are instantiating a new ContainerView1 controller. That won't help you; you need to call performSegueWithIdentifier:sender: on the instance already created.
Depending on how your Storyboard and code are set up, you need to find a way to get a hold of the embedded view controller.
For this set up:
You could do something like this in the main (hosting) view controller:
#property (weak, nonatomic) IBOutlet UIView *childView;
#property (weak,nonatomic) UINavigationController *container;
...
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([segue.identifier isEqualToString:#"embedContainer1"]) {
self.container = segue.destinationViewController;
}
}
-(IBAction)doIt:(id)sender {
[self.container.viewControllers[0] performSegueWithIdentifier:#"pushSegue" sender:nil];
}
By implementing prepareForSegue:sender:, you're able to get a reference to the child viewcontroller; cleaner then going through the array of childViewControllers IMHO.
I have created a my own custom cell in a nib file and I am receiving an error I don't understand.
[self presentViewController:_myMail animated:YES completion:nil];
In this line I receive there error No visible #interface for "LeadCell" declares the selector presentViewController:animated:completion:
LeadCell is the name of the controller for the custom. I would like to create an action where the user clicks the button and it opens a mail composer view to send an email.
Any clarity would be appreciated.
A clean way to solve this problem would be to store the view controller with your custom cell, like this:
#interface LeadCell {
__weak UIViewController *ctrl;
}
-(id)initWithViewController:(UIViewController*)c;
...
#end
#implementation LeadCell
-(id)initWithViewController:(UIViewController*)c {
if (self = [super init]) {
ctlr = c;
}
return self;
}
#end
When you create new cells in your "cell for row at index path", pass the view controller to the initializer of the cell. This way, the cell would be able to "find" the controller, letting you code your action by using ctrl instead of self:
[ctrl presentViewController:_myMail animated:YES completion:nil];
Because you are trying to present a view controller from subclass of UITableViewCell. The UITableViewCell have no such method for presenting the view controller.
The presentViewController method is declared for ViewController and it's subclasses.
The tableViewCell is not a viewcontroller it's a view. So there is no method like presentViewController for UITableViewCell.
I am very new to iPhone app development.
I am developing one example application for iPhone emulator using Objective-C++ and std CPP.
I have two views in my application, on some events from CPP code i am displaying second view using following code from the first view controller.
// Defined in .h file
secondViewScreenController *mSecondViewScreen;
// .mm file Code gets called based on event from CPP (common interface function between Objective-C++ and CPP code)
mSecondViewScreen = [[secondViewScreenController alloc] initWithNibName:nil bundle:nil];
[self presentModalViewController:mSecondViewScreen animated:YES];
I am able to see second view coming on screen, but problem is that i am unable to end/remove second view controller from first view controller.
How can i remove second view controller from first view controller using second view controller's pointer or using any other method.
To remove second view i have following code in second view controller file, which gets called on button click event of second view.
// In .mm of second view controller.
- (IBAction)onEndBtnClicked:(UIButton *)sender
{
[self dismissModalViewControllerAnimated:NO];
[self.navigationController popViewControllerAnimated:YES];
}
Above code works perfectly, when i click on the seconds view's end button it removes the second view controller from the screen and navigets to first view, how can i use same code to remove second view from the first view controller.
I tied to use NSNotificationCenter to send event from first view to second view to call the function onEndBtnClicked but it is not working.
What is the proper way of doing it?
OSX version: 10.5.8 and Xcode version: 3.1.3
In the secondViewController create a protocol like:
#protocol SecondViewScreenControllerDelegate <NSObject>
- (void)secondViewScreenControllerDidPressCancelButton:(UIViewController *)viewController sender:(id)sender;
// Any other button possibilities
#end
Now you have to add a property in the secondViewController class:
#property (weak, nonatomic) id<SecondViewScreenControllerDelegate> delegate;
You sinthesize it in the secondViewController implementation:
#synthesize delegate = _delegate;
Finally all you have to do is implement the protocol in your firstViewController and set the secondViewController properly prior presenting it:
#interface firstViewController : UIViewController <SecondViewScreenControllerDelegate>
...
#implementation firstViewController
- (void)secondViewScreenControllerDidPressCancelButton:(UIViewController *)viewController sender:(id)sender
{
// Do something with the sender if needed
[viewController dismissViewControllerAnimated:YES completion:NULL];
}
Then when presenting the secondViewController from the first:
UIViewController *sec = [[SecondViewController alloc] init]; // If you don't need any nib don't call the method, use init instead
sec.delegate = self;
[self presentViewController:sec animated:YES completion:NULL];
And ready. Whenever you want to dismiss the secondViewController from the first, just call: (inside the secondViewController implementation)
[self.delegate secondViewScreenControllerDidPressCancelButton:self sender:nil]; // Use nil or any other object to send as a sender
All that happens is that you send a pointer of the secondViewController that you can use from the first. Then you can work with it without problem. No C++ needed. In Cocoa you won't need C++. Almost everything can be done with Objective-C, and it's more dynamic.
If there are only two views in your application then use
- (IBAction)onEndBtnClicked:(UIButton *)sender
{
[self dismissModalViewControllerAnimated:NO];
}
remove line below:
[self.navigationController popViewControllerAnimated:YES];
as it is you are dismissing second view then why you want to remove it from first view.
I did find an answer to this title and I did do a little research but I'm still not getting the flow. Here is what I want to happen:
1) click a button on the presenter view to open a modal view. 2) retrieve some value and click a button to close the modal view....sending the value to the presentor view and execute a method.
I get that this works like a callback but I still can't figure out where to put the callback stuff.
So, how exactly do I do this? A) In the presentViewController completion block, should I include the presenter view method to execute when modal view is completed?
Or: B) In the modal view's dismissViewControllerAnimated completion block, should I include the presenter view method to execute when modal view is completed?
Can somebody help me with some sample code? Or at least help me get the flow of which block to put the code in?
Thank you, P
You talk about completion blocks so I am assuming you do not want to use delegates.
In the viewController that will be presented modally you need to provide a public completion handler, that will be called when it is dismissed.
#interface PresentedViewController : UIViewController
#property (nonatomic, strong) void (^onCompletion)(id result);
#end
Then in the implementation you need to call this completion block on dismissal. Here I assume the viewController is dismissed on a button click
- (IBAction)done:(id)sender
{
if (self.onCompletion) {
self.onCompletion(self.someRetrievedValue);
}
}
Now back in the viewController that presented the modal you need to provide the actual completion block - normally when you create the viewController
- (IBAction)showModal;
{
PresentedViewController *controller = [[PresentedViewController alloc] init];
controller.onCompletion = ^(id result) {
[self doSomethingWithTheResult:result]
[self dismissViewControllerAnimated:YES completion:nil];
}
[self presentViewController:controller animated:YES completion:nil];
}
This will create the new viewController to be presented modally and define what needs to happen on completion.
You can do this with delegates, that's the way Apple seems to recommend, but that seems like overkill to me. You have a reference to the presenter with the presentingViewController property, so you can just set the value of a property in the presenter from the presented controller in the button click method:
self.presentingViewController.someProp = self.theValueToPass;
[self dismissViewControllerAnimated:YES];
Using delegates is a good way to handle this:
In your PresentedViewController.h
#protocol PresentedViewControllerDelegate <NSObject>
-(void) viewWillDismiss;
#end
#property (nonatomic, weak) id <PresentedViewController> delegate;
Then in your PresentingViewController.h, you would subscribe to this delegate
#interface PresentingViewController : UIViewController <PresentedViewControllerDelegate>
in the .m you must implement the delegate method
- (void) viewWillDismiss {
}
and before you present the view controller set the delegate property you made as self.
presentingViewController.delegate = self;
Obviously not every implementation detail has been done here, but this should get you started.
I know this question has been asked several times and I did read existing posts on this topic but I still need help.
I have 2 UIViewControllers - parent and child. I display the child UIViewController using the presentModalViewController as below:
ChildController *child =
[[ChildController alloc] initWithNibName:#"ChildView" bundle:nil];
[self presentModalViewController:child animated:YES];
[child release];
The child view has a UIPickerView. When user selects an item from UIPickerView and clicks done, I have to dismiss the modal view and display the selected item on a UITextField in the parent view.
In child's button click delegate, I do the following:
ParentController *parent =
(ParentController *)[self.navigationController parentViewController];
[parent.myTextField setText:selectedText];
[self dismissModalViewControllerAnimated:YES];
Everything works without errors. But I don't know how to load the parent view so that it displays the updated UITextField.
I tried
[parent reloadInputViews];
doesn' work. Please help.
Delegation is the way to go. I know some people that may be looking for an easier solution but trust me I have tried others and nothing works better than delegation. So anyone having the same problem, go read up on delegation and follow it step by step.
In your subviewcontroller.h - declare a protocol and declare delegate mthods in it.
#protocol myDelegate
-(void)clickedButton:(subviewcontroller *)subController;
#end
In your subviewcontroller.h, within #interface:
id<myDelegate> delegate;
#property (nonatomic, assign) id<myDelegate> delegate;
NSString *data;
-(NSString *)getData;
In your subviewcontroller.m, synthesize myDelegate. Add the following code to where you want to notify your parentviewcontroller that the subview is done doing whatever it is supposed to do:
[delegate clickedButton:self];
and then handle getData to return whatever data you want to send to your parentviewcontroller
In your parentviewcontroller.h, import subviewcontroller.h and use it's delegate
#import "subviewcontroller.h"
#interface parentviewcontroller : VUIViewController <myDelegate>
{}
In your parentviewcontroller.m, implement the delegate method
- (void)clickedButton:(subviewcontroller *)subcontroller
{
NSString *myData = [subcontroller getData];
[self dimissModalViewControllerAnimated:YES];
[self reloadInputViews];
}
Don't forget memory management!
If a low-memory warning comes in during your modal view's display, the parent's view will be unloaded. Then parent.myTextField is no longer referring to the right text field until the view is reloaded. You can force a reload of the view just by calling parent.view;
However, a better idea might be to have the parent view have a String property that can be set by the child view. Then, when the parent view reappears, put that data into the text field, inside viewWillAppear: for example. You'd want to have the value set to some default value for when the parent view initially shows up too.
-(void) viewWillAppear:(BOOL) animated doesn't get called for me either, exactly when it's a modal view controller. No idea why. Not incorrectly overridden anywhere in this app, and the same problem occurs on the other 2 apps I'm working on. I really don't think it works.
I've used the delegate approach before, but I think that following approach is pretty good as well.
I work around this by adding a private category to UIViewController, like so:
.h file:
#interface UIViewController(Extras)
// returns true if this view was presented via presentModalViewController:animated:, false otherwise.
#property(readonly) BOOL isModal;
// Just like the regular dismissModalViewController, but actually calls viewWillAppear: on the parent, which hasn't been working for me, ever, for modal dialogs.
- (void)dismissModal: (BOOL) animated;
#end
and .m file:
#implementation UIView(Extras)
-(BOOL) isModal
{
return self == self.parentViewController.modalViewController;
}
- (void)dismissModal: (BOOL) animated
{
[self.parentViewController viewWillAppear: animated];
[self dismissModalViewControllerAnimated: animated];
}
#end
which I can now call like this when I want to dismiss the dialog box:
// If presented as a modal view, dismiss yourself.
if(self.isModal)
[self dismissModal: YES];
and now viewWillAppear is correctly called.
And yes, I'm donating a bonus 'isModal' property, so that the modal view can tell how it was being presented, and dismiss itself appropriately.