i just learn how to change switch between views with push and pop.
now, to my second view i add a label witch i wand to change her value every time my second view is push.
i add the label, connect her to my file owner's and i use viewdidload to change her value.
when i entered to my second view nothing is happed. but when i use viewdidapper all work perfect(but it take a second until the label value is update).
my code is:
mysecondviewcontroller.h:
#interface SecondViewController : UIViewController
{
IBOutlet UILabel *textLabel;
NSString *label;
}
#property (copy) NSString *label;
#end
mysecondviewcontroller.m(ofcourse i synthesize label):
-(void)viewDidAppear:(BOOL)animated
{
textLabel.text = label;
NSLog(#"viewdidapper2");
}
- (void)viewDidLoad
{
textLabel.text = label;
[super viewDidLoad];
NSLog(#"viewdidload2");
// Do any additional setup after loading the view from its nib.
}
my firstviewcontroller.m(IBAction):
- (IBAction)pushViewController:(id)sender
{
static int count = 1;
SecondViewController *secondVieController = [[SecondViewController alloc] init];
[self.navigationController pushViewController:secondVieController animated:YES];
secondVieController.title = #"second";
secondVieController.label = [NSString stringWithFormat:#"number: %d", count];
count++;
}
what is the problem in my viewdidload?
thanks!
If you're using viewDidLoad, you need to call the super function before doing anything else.
- (void)viewDidLoad
{
[super viewDidLoad];
textLabel.text = label;
NSLog(#"viewdidload2");
// Do any additional setup after loading the view from its nib.
}
I think that there is another issue, you are setting secondVieController.label after pushing the view controller, but this means at the time that viewDidLoad runs, secondVieController.label is still empty. This should fix it.
- (IBAction)pushViewController:(id)sender
{
static int count = 1;
SecondViewController *secondVieController = [[SecondViewController alloc] init];
secondVieController.title = #"second";
secondVieController.label = [NSString stringWithFormat:#"number: %d", count];
[self.navigationController pushViewController:secondVieController animated:YES];
count++;
}
If you Want to Update Label Every Time when View Loaded Then You have to Write the code in to Viewwillappear Method.
Related
I use storyboard in a OS X cocoa application project with a SplitView controller and 2 others view controller LeftViewController and RightViewController.
In the LeftViewController i have a tableView that display an array of name. The datasource and delegate of the tableview is the LeftViewController.
In the RightViewController i just have a centered label that display the select name. I want to display in the right view the name selected in the left view.
To configure the communication between the 2 views controllers i use the AppDelegate and i define 2 property for each controller in AppDelegate.h
The 2 property are initialized in the viewDidLoad of view controller using the NSInvocation bellow :
#implementation RightViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.
id delg = [[NSApplication sharedApplication] delegate];
SEL sel1 = NSSelectorFromString(#"setRightViewController:");
NSMethodSignature * mySignature1 = [delg methodSignatureForSelector:sel1];
NSInvocation * myInvocation1 = [NSInvocation
invocationWithMethodSignature:mySignature1];
id me = self;
[myInvocation1 setTarget:delg];
[myInvocation1 setSelector:sel1];
[myInvocation1 setArgument:&me atIndex:2];
[myInvocation1 invoke];
}
I have the same in LeftViewController.
Then if i click on a name in the table view, i send a message to the delegate with the name in parameter and the delegate update the label of the RightViewController with the given name. It works fine but according to apple best practice it’s not good.
Is there another way to communicate between 2 view controller inside a storyboard ?
I've already read a lot of post but found nothing for OS X.
You can download the simple project here : http://we.tl/4rAl9HHIf1
This is more advanced topic of app architecture (how to pass data).
Dirty quick solution: post NSNotification together with forgotten representedObject:
All NSViewControllers have a nice property of type id called representedObject. This is one of the ways how to pass data onto NSViewController. Bind your label to this property. For this simple example we will set representedObject some NSString instance. You can use complex object structure as well. Someone can explain in comments why storyboards stopped to show representedObject (Type safety in swift?)
Next we add notification observer and set represented object in handler.
#implementation RightViewController
- (void)viewDidLoad
{
[super viewDidLoad];
[[NSNotificationCenter defaultCenter] addObserverForName:#"SelectionDidChange" object:nil queue:[NSOperationQueue mainQueue] usingBlock:^(NSNotification * _Nonnull note) {
//[note object] contains our NSString instance
[self setRepresentedObject:[note object]];
}];
}
#end
Left view controller and its table:
Once selection changes we post a notification with our string.
#interface RightViewController () <NSTableViewDelegate, NSTableViewDataSource>
#end
#implementation RightViewController
- (NSInteger)numberOfRowsInTableView:(NSTableView *)tableView
{
return [[self names] count];
}
- (nullable id)tableView:(NSTableView *)tableView objectValueForTableColumn:(nullable NSTableColumn *)tableColumn row:(NSInteger)row
{
return [self names][row];
}
- (NSArray<NSString *>*)names
{
return #[#"Cony", #"Brown", #"James", #"Mark", #"Kris"];
}
- (void)tableViewSelectionDidChange:(NSNotification *)notification
{
NSTableView *tableView = [notification object];
NSInteger selectedRow = [tableView selectedRow];
if (selectedRow >= 0) {
NSString *name = [self names][selectedRow];
if (name) {
[[NSNotificationCenter defaultCenter] postNotificationName:#"SelectionDidChange" object:name];
}
}
}
PS: don't forget to hook tableview datasource and delegate in storyboard
Why is this solution dirty? Because once your app grows you will end up in notification hell. Also view controller as data owner? I prefer window controller/appdelegate to be Model owner.
Result:
AppDelegate as Model owner.
Our left view controller will get it's data from AppDelegate. It is important that AppDelegate controls the data flow and sets the data (not the view controller asking AppDelegate it's table content cause you will end up in data synchronization mess). We can do this again using representedObject. Once it's set we reload our table (there are more advanced solutions like NSArrayController and bindings). Don't forget to hook tableView in storyboard. We also modify tableview's delegate methos the tableViewSelectionDidChange to modify our model object (AppDelegate.selectedName)
#import "LeftViewController.h"
#import "AppDelegate.h"
#interface LeftViewController () <NSTableViewDelegate, NSTableViewDataSource>
#property (weak) IBOutlet NSTableView *tableView;
#end
#implementation LeftViewController
- (NSInteger)numberOfRowsInTableView:(NSTableView *)tableView
{
return [[self representedObject] count];
}
- (nullable id)tableView:(NSTableView *)tableView objectValueForTableColumn:(nullable NSTableColumn *)tableColumn row:(NSInteger)row
{
return [self representedObject][row];
}
- (void)setRepresentedObject:(id)representedObject
{
[super setRepresentedObject:representedObject];
//we need to reload table contents once
[[self tableView] reloadData];
}
- (void)tableViewSelectionDidChange:(NSNotification *)notification
{
NSTableView *tableView = [notification object];
NSInteger selectedRow = [tableView selectedRow];
if (selectedRow >= 0) {
NSString *name = [self representedObject][selectedRow];
[(AppDelegate *)[NSApp delegate] setSelectedName:name];
} else {
[(AppDelegate *)[NSApp delegate] setSelectedName:nil];
}
}
In RightViewController we delete all code. Why? Cause we will use binding AppDelegate.selectedName <--> RightViewController.representedObject
#implementation RightViewController
#end
Finally AppDelegate. It needs to expose some properties. What is interesting is how do I get my hands on all my controllers? One way (best) is to instantiate our own window controller and remember it as property. The other way is to ask NSApp for it's windows (be careful here with multiwindow app). From there we just ask contentViewController and loop through childViewControllers. Once we have our controllers we just set/bind represented objects.
#interface AppDelegate : NSObject <NSApplicationDelegate>
#property (nonatomic) NSString *selectedName;
#property (nonatomic) NSMutableArray <NSString *>*names;
#end
#import "AppDelegate.h"
#import "RightViewController.h"
#import "LeftViewController.h"
#interface AppDelegate () {
}
#property (weak, nonatomic) RightViewController *rightSplitViewController;
#property (weak, nonatomic) LeftViewController *leftSplitViewController;
#property (strong, nonatomic) NSWindowController *windowController;
#end
#implementation AppDelegate
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
_names = [#[#"Cony", #"Brown", #"James", #"Mark", #"Kris"] mutableCopy];
_selectedName = nil;
NSStoryboard *storyboard = [NSStoryboard storyboardWithName:#"Main"
bundle:[NSBundle mainBundle]];
NSWindowController *windowController = [storyboard instantiateControllerWithIdentifier:#"windowWC"];
[self setWindowController:windowController];
[[self windowController] showWindow:nil];
[[self leftSplitViewController] setRepresentedObject:[self names]];
[[self rightSplitViewController] bind:#"representedObject" toObject:self withKeyPath:#"selectedName" options:nil];
}
- (RightViewController *)rightSplitViewController
{
if (!_rightSplitViewController) {
NSArray<NSViewController *>*vcs = [[[self window] contentViewController] childViewControllers];
for (NSViewController *vc in vcs) {
if ([vc isKindOfClass:[RightViewController class]]) {
_rightSplitViewController = (RightViewController *)vc;
break;
}
}
}
return _rightSplitViewController;
}
- (LeftViewController *)leftSplitViewController
{
if (!_leftSplitViewController) {
NSArray<NSViewController *>*vcs = [[[self window] contentViewController] childViewControllers];
for (NSViewController *vc in vcs) {
if ([vc isKindOfClass:[LeftViewController class]]) {
_leftSplitViewController = (LeftViewController *)vc;
break;
}
}
}
return _leftSplitViewController;
}
- (NSWindow *)window
{
return [[self windowController] window];
}
//VALID SOLUTION IF YOU DON'T INSTANTIATE STORYBOARD
//- (NSWindow *)window
//{
// return [[NSApp windows] firstObject];
//}
#end
Result: works exactly the same
PS: If you instantiate own window Controller don't forget to delete initial controller from Storyboard
Why is this better? Cause all changes goes to model and models sends triggers to redraw views. Also you will end up in smaller view controllers.
What can be done more? NSObjectController is the best glue between your model objects and views. It also prevents retain cycle that sometimes can happen with bindings (more advanced topic). NSArrayController and so on...
Caveats: not a solution for XIBs
I managed to get what i want by adding the following code in AppDelegate.m :
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
// Insert code here to initialize your application
//
NSStoryboard *storyboard = [NSStoryboard storyboardWithName:#"Main"
bundle:[NSBundle mainBundle]];
self.windowController = [storyboard instantiateControllerWithIdentifier:#"windowController"];
self.window = self.windowController.window;
self.splitViewController = (NSSplitViewController*)self.windowController.contentViewController;
NSSplitViewItem *item0 = [self.splitViewController.splitViewItems objectAtIndex:0];
NSSplitViewItem *item1 = [self.splitViewController.splitViewItems objectAtIndex:1];
self.leftViewController = (OMNLeftViewController*)item0.viewController;
self.rightViewController = (OMNRightViewController*)item1.viewController;
[self.window makeKeyAndOrderFront:self];
[self.windowController showWindow:nil];
}
We also need to edit the storyboard NSWindowController object as follow :
Uncheck the checkbox 'Is initial controller' because we add it programmatically in AppDelegate.m.
Now the left and right view can communicate. Just define a property named rightView in OMNLeftViewController.h :
self.leftViewController.rightView = self.rightViewController;
I have a subclass of UIViewController -> MyPopUpViewController
#protocol MyPopUpViewController Delegate;
#interface MyPopUpViewController : UIViewController
{
}
#property (nonatomic, strong) id <MyPopUpViewControllerDelegate> delegate;
-(IBAction) buttonPressed:(id)sender;
#end
#protocol MyPopUpViewControllerDelegate
-(void) popupButtonPressed: (MyPopUpViewController*)controller;
#end
I cannot have this MyPopUpViewController as an instance variable because this comes externally, and there could be many and multiple of these popups can be up. So far I tried this, and it crashes on the delegate call due to not being retained:
MyMainViewController:
-(void)externalNotificationReceived: (NSString*) sentMessage
{
MyPopUpViewController *popupView = [[MyPopUpViewController alloc] init];
popupView.delegate = self;
[self.view addSubview:popupView.view];
[popupView setInfo :sentMessage :#"View" :#"Okay"];
popupView.view.frame = CGRectMake(0, -568, 320, 568);
popupView.view.center = self.view.center;
}
-(void)popupButtonPressed:(MyPopUpViewController *)controller :(int)sentButtonNumber
{
NSLog(#"Popup Delegate Called");
[controller.view removeFromSuperview];
controller.delegate = nil;
controller = nil;
}
Once the popup comes up, and when the ok button is tapped, it crashes and never gets to that NSLog. How can I change
MyPopUpViewController *popupView = [[MyPopUpViewController alloc] init];
..so it would retain without making it an instance variable?
Thanks in advance.
You should be doing proper view controller containment by calling addChildViewController:.
- (void)externalNotificationReceived: (NSString*) sentMessage {
MyPopUpViewController *popupView = [[MyPopUpViewController alloc] init];
popupView.delegate = self;
[popupView setInfo :sentMessage :#"View" :#"Okay"];
popupView.view.frame = CGRectMake(0, -568, 320, 568);
popupView.view.center = self.view.center;
[self addChildViewController:popupView];
[self.view addSubview:popupView.view];
[popupView didMoveToParentViewController:self];
}
This will keep a proper reference to the view controller as well as properly pass various view controller events. Read about this in the docs for UIViewController and the "View Controller Programming Guide for iOS".
BTW - you should name your methods better. Example:
popupButtonPressed::
should be named:
popupButtonPressed:buttonNumber:
Usually delegates are weak-referenced instead of strong. I, myself, would name it something else as to not confuse other people.
Also, the following bit of code will have no effect:
-(void)popupButtonPressed:(MyPopUpViewController *)controller :(int)sentButtonNumber
{
...
controller = nil;
}
the controller would be released (set to nil) automatically at the end of the scope.
I am creating an app where you press a button and it opens up your contacts list. You can then select the contact you want to add and it imports their name and email into the app. I currently have that information going into labels but I want to add it to a table view cell. How would I do this?
My Code:
.h:
#import <UIKit/UIKit.h>
#import <AddressBookUI/AddressBookUI.h>
#interface FirstViewController : UIViewController <ABPeoplePickerNavigationControllerDelegate>
- (IBAction)showPicker:(id)sender;
#property (weak, nonatomic) IBOutlet UILabel *firstName;
#property (weak, nonatomic) IBOutlet UILabel *email;
#end
.m:
#import "FirstViewController.h"
#interface FirstViewController ()
#end
#implementation FirstViewController
#synthesize firstName;
#synthesize email;
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (IBAction)showPicker:(id)sender {
ABPeoplePickerNavigationController *picker =
[[ABPeoplePickerNavigationController alloc] init];
picker.peoplePickerDelegate = self;
[self presentModalViewController:picker animated:YES];
}
- (void)peoplePickerNavigationControllerDidCancel:
(ABPeoplePickerNavigationController *)peoplePicker
{
[self dismissModalViewControllerAnimated:YES];
}
- (BOOL)peoplePickerNavigationController:
(ABPeoplePickerNavigationController *)peoplePicker
shouldContinueAfterSelectingPerson:(ABRecordRef)person {
[self displayPerson:person];
[self dismissModalViewControllerAnimated:YES];
return NO;
}
- (BOOL)peoplePickerNavigationController:
(ABPeoplePickerNavigationController *)peoplePicker
shouldContinueAfterSelectingPerson:(ABRecordRef)person
property:(ABPropertyID)property
identifier:(ABMultiValueIdentifier)identifier
{
return NO;
}
- (void)displayPerson:(ABRecordRef)person
{
NSString* name = (__bridge_transfer NSString*)ABRecordCopyValue(person,
kABPersonFirstNameProperty);
self.firstName.text = name;
ABMultiValueRef emails = ABRecordCopyValue(person, kABPersonEmailProperty);
NSString *emailId = (__bridge NSString *)ABMultiValueCopyValueAtIndex(emails, 0);//0 for "Home Email" and 1 for "Work Email".
self.email.text = emailId;
}
#end
OK, I am going to explain how you programmatically implement a very basic table view controller. It will be up to you, though, to figure out how to integrate this into your application.
Let's start with the header file, let's call it MyTableViewController.h:
#interface MyTableViewController : UIViewController <UITableViewDelegate, UITableViewDataSource>
{
}
#end
As you can see, your controller class adopts the protocols UITableViewDelegate and UITableViewDataSource.
Now let's look at a first snippet from the implementation file MyTableViewController.m. Your first job, obviously, is to create the controller's view. You do this in your controller's loadView method. If you want to learn more about the view life cycle and how to program a UIViewController I suggest you read the UIViewController class reference and the accompanying View Controller Programming Guide.
- (void) loadView
{
// Give the view some more or less arbitrary initial size. It will be
// resized later when it is actually displayed
CGRect tableViewFrame = CGRectMake(0, 0, 320, 200);
UITableView* tableView = [[[UITableView alloc] initWithFrame:tableViewFrame style:UITableViewStyleGrouped] autorelease];
self.view = tableView;
// Here we make sure that the table view will take as much horizontal
// and vertical space as it can get when it is resized.
UIViewAutoresizing autoresizingMask = (UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight);
tableView.autoresizingMask = autoresizingMask;
// We need to tell the table view that we are both its delegate and
// its data source.
tableView.delegate = self;
tableView.dataSource = self;
}
Just to let you know: You can omit loadView entirely if your controller is a subclass of UITableViewController, but I deliberately do not take that shortcut so that I can show you how a table view needs a delegate and a data source. Most important ist the data source.
In the next snippet in MyTableViewController.m we are going to implement some basic UITableViewDataSource methods. For this you need to understand how a table view is structured: A table view is divided into sections, and each section has a number of cells. The point of having sections is to visually separate groups of cells, with an optional section header or footer. I am not going into details here, though, to keep this simple.
- (NSInteger) numberOfSectionsInTableView:(UITableView*)tableView
{
// Let's keep it simple: We want just one section
return 1;
}
- (NSInteger) tableView:(UITableView*)tableView numberOfRowsInSection:(NSInteger)section
{
// Let's keep it simple: We want just one row, or table view cell.
// Since we only have one section (see above) we don't have to look
// at the section parameter.
return 1;
}
And now, finally, the centerpiece where you create your table view cell. Again, this is a UITableViewDataSource method that we implement. Note that we do not need to inspect the indexPath parameter only because we know that we only have one section and one row. In a real world application you will probably have to write switch-case or if-else statements that examine indexPath.section and indexPath.row so that you can distinguish between the different cells you need to create.
- (UITableViewCell*) tableView:(UITableView*)tableView cellForRowAtIndexPath:(NSIndexPath*)indexPath
{
// This is very important for your future table view implementations:
// Always ask the table view first if it already has a cell in its
// cache. If you don't do this your table view will become slow when
// it has many cells.
NSString* identifier = #"MyTableViewCell";
UITableViewCell* cell = [tableView dequeueReusableCellWithIdentifier:identifier];
if (cell == nil)
{
// Aha, the table view didn't have a cell in its cache, so we must
// create a new one. We use UITableViewCellStyleValue1 so that the
// cell can display two pieces of information.
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:identifier] autorelease];
}
// Regardless of whether we got the cell from the table view's cache
// or create a new cell, we must now fill it with content.
// First, obtain the information about the person from somewhere...
NSString* personName = ...;
NSString* personEmail = ...;
// ... then add the information to the table cell
cell.textLabel.text = personName;
cell.detailTextLabel.text = personEmail;
return cell;
}
As a final nicety, we implement a UITableViewDelegate method:
- (void) tableView:(UITableView*)tableView didSelectRowAtIndexPath:(NSIndexPath*)indexPath
{
[tableView deselectRowAtIndexPath:indexPath animated:NO];
// Here you can react to the user tapping on the cell. If you
// don't want the user to be able to select a cell you can
// add the following line to tableView:cellForRowAtIndexPath:
// cell.selectionStyle = UITableViewCellSelectionStyleNone;
}
It is difficult to tell how you should integrate this into your application. It all depends where you want to display the table view. Since you say you want to replace the two labels you already have, one possible approach could be this:
In Interface Builder, add the table view as a subview to the main view of your FirstViewController
Add an outlet to FirstViewController that you connect to the table view
Let FirstViewController adopt the protocols UITableViewDelegate and UITableViewDataSource
Connect FirstViewController to the delegate and data source outlets of the table view
Don't implement loadView from my example, you don't need it, you already have made all the connections etc. in Interface Builder
If you need further help with integration, I suggest that you ask a new question and possibly refer to this answer. Good luck.
How do I get a reference to the UIViewController of a touched view?
I am using a UIPanGestureRecognizer on the view of a UIViewController. Here's how I initialize it:
TaskUIViewController *thisTaskController = [[TaskUIViewController alloc]init];
[[self view]addSubview:[thisTaskController view]];
UIPanGestureRecognizer *panRec = [[UIPanGestureRecognizer alloc]initWithTarget:self action:#selector(handlePan:)];
[[thisTaskController view] addGestureRecognizer:panRec];
In the tiggered action triggered using the gesture recognizer I am able to get the view from the parameter using recognizer.view
- (IBAction)handlePan:(UIPanGestureRecognizer *)recognizer {
UIView *touchedView = [[UIView alloc]init];
touchedView = (UIView*)[recognizer view];
...
}
However what I really need is the underlying UIViewController of the view touched. How can I get a reference to the UIViewController that contains this view instead of only the UIView?
I would say that it is more a design issue than just getting a reference. So I would follow several simple advises:
Owner should catch events from its view. I.e. TaskUIViewController sould be a target to UIPanGestureRecognizer which you added to its view.
If a controller has a sub-controller and waits from its sub-controller some responses - implement this as delegate.
You have memory leak in your "handlePan:" method.
Here is a skeleton to solve your issue:
#protocol CallbackFromMySubcontroller <NSObject>
- (void)calbackFromTaskUIViewControllerOnPanGesture:(UIViewController*)fromController;
#end
#interface OwnerController : UIViewController <CallbackFromMySubcontroller>
#end
#implementation OwnerController
- (id)init
{
...
TaskUIViewController *thisTaskController = [[TaskUIViewController alloc] init];
...
}
- (void)viewDidLoad
{
...
[self.view addSubview:thisTaskController.view];
...
}
- (void)calbackFromTaskUIViewControllerOnPanGesture:(UIViewController*)fromController
{
NSLog(#"Yahoo. I got an event from my subController's view");
}
#end
#interface TaskUIViewController : UIViewController {
id <CallbackFromMySubcontroller> delegate;
}
#end
#implementation TaskUIViewController
- (id)initWithOwner:(id<CallbackFromMySubcontroller>)owner
{
...
delegate = owner;
...
}
- (void)viewDidLoad
{
UIPanGestureRecognizer *panRec = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(handlePan:)];
[self.view addGestureRecognizer:panRec];
[panRec release];
}
- (void)handlePan:(UIPanGestureRecognizer *)recognizer {
...
[delegate calbackFromTaskUIViewControllerOnPanGesture:self];
...
}
#end
[touchedView nextResponder] will return the UIViewController object that manages touchedView (if it has one) or touchedView's superview (if it doesn’t have a UIViewController object that manages it).
For more information, see the UIResponder Class Reference. (UIViewController and UIView are subclasses of UIResponder.)
In your case, since you happen to know that touchedView is your viewController's view (and not, for instance, a subview of your viewController's view), you can just use:
TaskUIViewController *touchedController = (TaskUIViewController *)[touchedView nextResponder];
In the more general case, you could work up the responder chain until you find an object of kind UIViewController:
id aNextResponder = [touchedView nextResponder];
while (aNextResponder != nil)
{
if ([aNextResponder isKindOfClass:[UIViewController class]])
{
// we have found the viewController that manages touchedView,
// so we break out of the while loop:
break;
}
else
{
// we have yet to find the managing viewController,
// so we examine the next responder in the responder chain
aNextResponder = [aNextResponder nextResponder];
}
}
// outside the while loop. at this point aNextResponder points to
// touchedView's managing viewController (or nil if it doesn't have one).
UIViewController *eureka = (UIViewController *)aNextResponder;
I'm sure I'm overlooking the obvious as I've got countless working buttons...but...for whatever reason this one is not cooperating...
I've added a UIButton (Rounded Rect) to a UIView subclass (DialogView) which is a subview of my view controller's view. This subview is created almost entirely in IB. I've wired up the button to (IBAction)okButtonPressed:(id)sender in IB to Touch Up Inside and created a corresponding method in DialogView. However when I "touch" this button it doesn't trigger the method. userInteractionEnabled is true for the VC's view, DialogView and the UIButton.
Thinking maybe initWithCoder had to do some frame manipulation or something I added the following which successfully logs to console.
- (id)initWithCoder:(NSCoder *)decoder {
if (self = [super initWithCoder:decoder]) {
NSLog(#"DialogView initWithCoder called");
}
return self;
}
In further exploration I wired up an IBOutlet to the button and then if I try to change the titleLabel from the view controller I notice that it get's severely truncated. Default text of say "Press Me!" set in IB displays fine when view is first drawn. But if I change the text...
self.DialogView.okButton.titleLabel.text = #"Not Working";
...it gets truncated to "N..."
Dunno if this is related. Probably...
Anyone see what I've screwed up here?
Edit (adding code related to showing UIButton):
From the View Controller:
self.DialogView = [[[NSBundle mainBundle] loadNibNamed:#"DialogView" owner:self options:nil] objectAtIndex:0];;
self.DialogView.myVC = self;
self.DialogView.backgroundColor = [UIColor clearColor];
self.DialogView.center = CGPointMake(self.view.frame.size.width / 2, self.view.frame.size.height / 2);
self.DialogView.nameLabel.text = loan.fullName;
self.DialogView.noteLabel.text = loan.summaryOfLoan;
self.DialogView.amountLabel.text = [currencyFormatter stringFromNumber:loan.originalAmount];
self.DialogView.alpha = 0.0;
[self.view addSubview:DialogView];
The UILabels all displaying as expected. As is the problem UIButton. I can see it I just can't interact with it!?!
DialogView's interface:
#class MyViewController;
#interface DialogView : UIView {
IBOutlet UILabel *nameLabel, *noteLabel, *amountLabel;
IBOutlet UIImageView *arrowView;
IBOutlet UIButton *okButton;
MyViewController *myVC;
}
#property (nonatomic, retain) UILabel *nameLabel, *noteLabel, *amountLabel;
#property (nonatomic, retain) UIImageView *arrowView;
#property (nonatomic, assign) MyViewController *myVC;
#property (nonatomic, retain) UIButton *okButton;
- (IBAction)okButtonPressed:(id)sender;
#end
And DialogView's implementation:
#import "DialogView.h"
#import "MyViewController.h"
#implementation DialogView
#synthesize nameLabel, noteLabel, amountLabel, arrowView, okButton;
#synthesize myVC;
- (void)dealloc {
[nameLabel release];
[noteLabel release];
[amountLabel release];
[arrowView release];
[okButton release];
[super dealloc];
}
- (id)initWithFrame:(CGRect)frame {
if (self = [super initWithFrame:frame]) {
// Initialization code
}
return self;
}
- (id)initWithCoder:(NSCoder *)decoder {
if (self = [super initWithCoder:decoder]) {
NSLog(#"DialogView initWithCoder called");
}
return self;
}
- (IBAction)okButtonPressed:(id)sender {
NSLog(#"pressed DialogView OK button");
[self.myVC.navigationController popViewControllerAnimated:YES];
}
- (void)drawRect:(CGRect)rect {
// Drawing code
}
#end
I thought that we should use -setTitle:forState: in order to set button's title ?
An other thought, did you check that the button's frame is not CGRectZero ? And by the way, all the frames for the view in the hierarchy ? And check that one superview in the hierarchy is not user interaction disabled ?
And, I think imageView does not respond to touches, do you have one in your code ?
I was just having more or less the same problem and I found that my containing view did not have "User Interaction Enabled".
Hope this helps.
Do you maybe have two buttons on top of one another? Change the IB project window to the detail view and see if your view has more buttons than you are expecting. Maybe you've wired up a button that's not actually getting the press you're expecting.