I'm using a TabBar app with a navigation item that includes a UISegmentedControl.
I've connected a method when the event "value changed" is caught.
The method always catch 0 as SegmentIndex...
Here's my header file :
#import <UIKit/UIKit.h>
#interface GraphNavController : UINavigationController {
IBOutlet UIImage *image;
CGPoint gestureStartPoint;
UISegmentedControl *segmentedControl;
}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event;
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event;
-(IBAction) segmentedControlIndexChanged;
-(void)journalier;
-(void)mensuel;
-(void)annuel;
#property (nonatomic, retain) IBOutlet UIImage *image;
#property (nonatomic, retain) IBOutlet UISegmentedControl *segmentedControl;
#end
The method is here :
-(IBAction) segmentedControlIndexChanged{
switch (self.segmentedControl.selectedSegmentIndex) {
case 0:
NSLog(#"1");
break;
case 1:
NSLog(#"2");
break;
case 2:
NSLog(#"3");
break;
default:
break;
}
}
I hope we will find a solution
Thanks a lot
A possible explanation for this problem is that self.segmentedControl is nil. Is self.segmentedControl as an IBOutlet? Or created in code? Check if self.segmentedControl == nil.
I had the same problem and fight with the bug of nill UISegmentedControl.
AND I FOUND THE ANSWER.
Sometimes you have the same problem but you have all connections in XIB.
THE PROBLEM: You have nill in self.segmentedControl.
In most situations when you have everything connected in XIB correct it will also not work.
THE CAUSE: Because of difference in studing the Objective-C we use different styles of writing code.
The Decision: For example we write in interface UISegmentedControl *control;
When you #synthesize how would you do that?
If you write #synthesize control=_control; you will always have nill when you write like that NSLog(#"%i",control.selectedSegmentIndex).
So we have the mistake in #synthesize or in Code.
Decision
For thou who write #synthesize control; use control.selectedSegmentIndex
For thou who write #synthesize control=_control; use _control.selectedSegmentIndex
And everything will work correct.
Related
How to hide my tableView which is declared in another class..
Here is my code snippet,
CRStoreView.h
#interface CRStoreView : UIView <UITableViewDelegate, UITableViewDataSource>{
....
}
#property (strong, nonatomic) IBOutlet UITableView *tblStore;
and i want to hide this tblStore in my new class(CRNextView.m)..
I tried this but table is not getting hide,
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
NSLog(#"touchesBegan");
CRStoreView *Obj = [[CRStoreView alloc] init];
[Obj.tblStore setHidden:YES];
}
How to Solve it ?
One method is to use delegates. Make CRStoreView a delegate of the CRNextView and call the setHidden method from the CRNextView on the delegate. Or you could pass the current instance of the CRStoreView to CRNextView and access the tableView object.
I'm working through the IOS HelloWorld example and I have a question regarding setting the delegate for a TextField. In the example it was as easy as control-dragging from the TextField to the ViewController. But now say I wanted to create a custom class to act as my delegate as so:
#import <Foundation/Foundation.h>
#interface SweetAssDelegate : NSObject <UITextFieldDelegate>
- (BOOL)textFieldShouldReturn:(UITextField *)theTextField;
#end
#import "SweetAssDelegate.h"
#implementation SweetAssDelegate
- (BOOL)textFieldShouldReturn:(UITextField *)theTextField
{
NSLog(#"Calling Delegate");
[theTextField resignFirstResponder];
return YES;
}
#end
How can I set this class to be the delegate of the TextField? As far as I can tell there is not way to accomplish this through the GUI. I tried manually setting the delegation after window load with no success:
#import "ViewController.h"
#import "SweetAssDelegate.h"
#interface ViewController ()
#property (weak, nonatomic) IBOutlet UITextField *inputField;
#end
- (void)viewDidLoad
{
[super viewDidLoad];
SweetAssDelegate *foo = [[SweetAssDelegate alloc] init];
[self.inputField setDelegate:foo];
NSLog(#"Delegate: %#", self.inputField.delegate);
}
I actually receive some sort of memory exception when bringing up the keyboard? Any ideas? Thanks.
As a side question, where should I always use viewDidLoad to initialize any variables? I noticed that init was not being called???
Your delegate object, foo, is allowed to fall out of scope and is released at the end of viewDidLoad and by the time the keyboard comes up, it doesn't exist anymore. Make it an ivar (or property) of your view controller, or otherwise make sure that foo doesn't fall out of scope at the end of viewDidLoad.
Thus, it could be something like:
#interface ViewController ()
#property (weak, nonatomic) IBOutlet UITextField *inputField;
#property (strong, nonatomic) SweetAssDelegate *foo;
#end
- (void)viewDidLoad
{
[super viewDidLoad];
self.foo = [[SweetAssDelegate alloc] init];
[self.inputField setDelegate:self.foo];
NSLog(#"Delegate: %#", self.inputField.delegate);
}
Your textfield delegate must have the implemented to be your textfield delegate I guess.
A delegate manages the communication between objects, which means your custom delegate must allow communication between objects and must provide methods, the textfield can work with...
Another example is a tableView:
You can make a custom delegate which implements the delegates and then calls some tableview related Methods...
Here this code might be interesting for you:
#interface myCustomDelegateForTextFields <UITextFieldDelegate>
#end
#implementation myCustomDelegateForTextFields
- (BOOL)textFieldShouldReturn:(UITextField *)theTextField {
return TRUE;
}
#end
#implementation ViewController
myCustomDelegateForTextFields *txtfielddelegate = [[myCustomDelegateForTextFields alloc] init];
UITextField *whatever;
whatever.delegate = txtfielddelegate;
//your textfield now listens to the BOOL method in your custom delegate
#end
Is it that what u were looking for? :)
you can ofc pack the myCustomDelegateForTextField delegate in another class and call the class
Here is the situation. I have a view controller titled "MyViewController." Within this view controller I have a text editing feature that uses subclassed buttons. The name of the UIButton Subclass is "ColorSwatch"
I have setup delegate/protocol methods in the "ColorSwatch.h" subclass as follow.
// ColorSwatch.h
#import <UIKit/UIKit.h>
#import <Foundation/Foundation.h>
#import <QuartzCore/QuartzCore.h>
#protocol ColorSwatchDelegate <NSObject>
- (void)fontColor:(UIColor *)color;
#end
#interface ColorSwatch : UIButton {
id <ColorSwatchDelegate> colorSwatchDelegate;
CAGradientLayer *gradient;
UIView *currentView;
UIColor *fontColor;
}
#property (nonatomic, retain) id <ColorSwatchDelegate> colorSwatchDelegate;
#property (nonatomic, retain) CAGradientLayer *gradient;
#property (nonatomic, retain) UIView *currentView;
#property (nonatomic, retain) UIColor *fontColor;
#end
Now in my "ColorSwatch.m" I have:
// ColorSwatch.m
#import "ColorSwatch.h"
#import <QuartzCore/QuartzCore.h>
#import "MyViewController.h"
#implementation ColorSwatch
#synthesize gradient;
#synthesize currentView;
#synthesize colorSwatchDelegate;
#synthesize fontColor;
-(void)setupView{
"Makes the subclassed buttons pretty"
}
-(id)initWithFrame:(CGRect)frame{
if((self = [super initWithFrame:frame])){
}
return self;
}
-(id)initWithCoder:(NSCoder *)aDecoder{
if((self = [super initWithCoder:aDecoder])){
[self setupView];
MyViewController *mvc = [[MyViewController alloc] initWithNibName:
#"MyViewController" bundle:nil];
self.colorSwatchDelegate = mvc;
}
return self;
}
-(void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
[self magnify:view];
fontColor = view.backgroundColor;
[self.colorSwatchDelegate fontColor:fontColor];
}
- (void)magnify:(UIView *)view
{
}
- (void)dealloc
{
[currentView release];
[gradient release];
[fontColor release];
[super dealloc];
}
#end
In the "MyViewController.h" I have:
// MyViewController.h
#import <UIKit/UIKit.h>
#import <QuartzCore/QuartzCore.h>
#import "ColorSwatch.h"
#interface MyViewController : UIViewController <ColorSwatchDelegate> {
UITextField *photoLabelTextField;
}
#property (nonatomic, retain) IBOutlet UITextField *photoLabelTextField;
#end
In the "MyViewController.m" I have:
- (void)fontColor:(UIColor *)color
{
NSLog(#"Selected Font Color");
[self.photoLabelTextField setTextColor:color];
}
Now the delegate method sort of works, meaning when I tap on a color button the
NSLog(#"Selected Font Color");
message gets fired. But the problem is that I cannot change the
[self.photoLabelTextField setTextColor:color];
property. I have tried numerous ways of changing the property, the only thing that I can do is send NSLogs, anything I try to change a property in the "MyViewController" Class nothing happens.
If anyone could please help me out, I would appreciate it.
Thank you
The problem is that the ColorSwatch is sending delegate messages to a dangling instance of MyViewController that it incorrectly allocated in it's initWithCoder: method.
UIControls shouldn't allocate ViewControllers to be their delegates... it goes the other way around.
Delete these lines...
// in ColorSwatch.m initWithCoder:
MyViewController *mvc = [[MyViewController alloc] initWithNibName:
#"MyViewController" bundle:nil];
self.colorSwatchDelegate = mvc;
Then, in MyViewController.m ...
- (void)viewDidLoad {
ColorSwatch *colorSwatchButton = [[ColorSwatch alloc] buttonWithType:UIButtonTypeCustom];
// or place a ColorSwatch in the xib, on MyViewController's view... But not before you
// you delete lines from initWithCoder, otherwise it's infinite circular allocation
colorSwatchButton.frame = CGRectMake(/* ... */);
colorSwatchButton addTarget:self action:#selector(csButtonPressed:) forControlEvent: UIControlEventTouchUpInside];
// and so on...
// now the important part:
colorSwatchButton.colorSwatchDelegate = self;
// see - the ViewController is in charge of allocation, sets itself up as the delegate
[self.view addSubview:colorSwatchButton];
}
Instead of building the button in code, you can use IB.
Step 1: make the delegate an outlet...
#property (nonatomic, retain) IBOutlet id <ColorSwatchDelegate> colorSwatchDelegate;
Step 2: draw the buttons in IB, and set their class to ColorSwatch.
Then you can skip the code I wrote in viewDidLoad.
Step 3: The newly placed button should now present an outlet in IB. You can drag from that to the MyViewController as you normally do.
There might be a connection problem in your IBOutlet photoLabelTextField, you may have forgotten to connect xib text field with your photoLabelTextField
A little background:
I'm a C# developer starting to mess with the iPhone (have an idea for a simple 2D game). The only MVC programming I've done was for the web (ASP.NET MVC) so although I do have an understanding in MVC, I can't wrap my mind around one thing. Here's an example to illustrate.
Say I have a simple app where all I want to do is display a big circle on the screen. I created a "View Based Application" and it gave me the basic classes to start with:
MVCConfusionAppDelegate
MVCConfusionViewController
Now since I'll be doing some custom drawing (I know I can add a subview and show the circle that way, but this is just a sample of a larger piece) I've added a class called MyCustomView and in Interface Builder set the View of the MVCConfusionViewController to be a MyCustomView.
Now here's the problem. I want to be able to set in code the size of how big the ball on the custom view should be. So I have a property on the MyCusomView like this:
#import <Foundation/Foundation.h>
#interface MyCustomView : UIView {
NSNumber *ballSize;
}
#property(nonatomic,retain)IBOutlet NSNumber *ballSize;
#end
#import "MyCustomView.h"
#implementation MyCustomView
#synthesize ballSize;
-(void)drawRect:(CGRect)rect
{
CGContextRef context = UIGraphicsGetCurrentContext();
[[UIColor redColor]set];
float floatValue = [self.ballSize floatValue];
CGRect ballRect = CGRectMake(50.0f, 50.0f,floatValue , floatValue);
CGContextFillEllipseInRect(context, ballRect);
}
#end
Then, here's my MVCConfusionViewController:
#import <UIKit/UIKit.h>
#import "MyCustomView.h"
#interface MVCConfusionViewController : UIViewController {
NSNumber *ballSize;
}
#property(nonatomic,retain)IBOutlet NSNumber *ballSize;
#end
#import "MVCConfusionViewController.h"
#import "MyCustomView.h"
#implementation MVCConfusionViewController
#synthesize ballSize;
- (void)viewDidLoad {
[super viewDidLoad];
MyCustomView *myView = (MyCustomView *)self.view;
myView.ballSize = self.ballSize;
}
And finally, the MVCConfusionAppDelegate:
#import <UIKit/UIKit.h>
#class MVCConfusionViewController;
#interface MVCConfusionAppDelegate : NSObject <UIApplicationDelegate> {
UIWindow *window;
MVCConfusionViewController *viewController;
}
#property (nonatomic, retain) IBOutlet UIWindow *window;
#property (nonatomic, retain) IBOutlet MVCConfusionViewController *viewController;
#end
#import "MVCConfusionAppDelegate.h"
#import "MVCConfusionViewController.h"
#import "MyCustomView.h"
#implementation MVCConfusionAppDelegate
#synthesize window;
#synthesize viewController;
- (void)applicationDidFinishLaunching:(UIApplication *)application {
viewController.ballSize = [NSNumber numberWithInt:200];
[window addSubview:viewController.view];
[window makeKeyAndVisible];
}
- (void)dealloc {
[viewController release];
[window release];
[super dealloc];
}
#end
As you can see, there's an ugly cast in my viewDidLoad method. I was hoping I'd be able to make the connection of the ballSize properties in IB, but it won't let me.
So my question simply is, what's the correct way of passing this data from my view controller to my view without doing that cast? I know I'm missing something fundamental, but I just don't see it. Any help would be greatly appreciated!
EDIT: Here's the source code. http://bit.ly/uKyp9 Maybe someone can have a look and see if I'm doing anything wrong.
Are you trying to connect one IBOutlet (in the controller) to another IBOutlet (in the view)? Unfortunately, I don't think it's that easy :-)
You're also storing the data (ballSize) in the controller and the view.
I'd make MVCConfusionViewController a data source for MyCustomView, and then let MyCustomView ask its datasource for the ballSize, inside the -drawRect: method.
#class MyCustomView;
#protocol MyCustomViewDataSource
- (NSNumber *)ballSizeForMyCustomView:(MyCustomView *)view;
#end
#interface MyCustomView {
id<MyCustomViewDataSource> dataSource;
}
#property (nonatomic, assign) IBOutlet id<MyCustomViewDataSource> dataSource;
#end
#implementation MyCustomView
- (void)drawRect:(CGRect) rect {
if (self.dataSource == nil) {
// no data source, so we don't know what to draw
return;
}
float floatValue = [[self.dataSource ballSizeForMyCustomView:self] floatValue];
// ...
}
#end
In Interface Builder, hook MVCConfusionViewController up to the view's dataSource property. Then implement the protocol:
#interface MVCConfusionViewController : UIViewController <MyCustomViewDataSource> {
[...]
}
[...]
#end
#implementation MVCConfusionViewController
- (NSNumber *)ballSizeForMyCustomView:(MyCustomView *)view {
return self.ballSize;
}
#end
This way your view controller could also be the data source for multiple MyCustomViews, because the protocol method takes a MyCustomView as an argument.
If you need more than one ball, have a look at the UITableViewDataSource and implement similar methods, something like:
-(NSInteger)numberOfBallsInMyCustomView:(MyCustomView *)view;
-(NSNumber *)myCustomView:(MyCustomView *) ballSizeAtIndex:(NSInteger)index;
Your view should already be set in IB, so you can use it as is. If you want to use MyCustomView, you can do it like this:
- (void)viewDidLoad {
[super viewDidLoad];
CGRect frame = CGRectMake(0, 0, 320, 480);
MyCustomView *myView = [[MyCustomView alloc] initWithFrame:frame];
myView.backgroundColor = [UIColor greenColor];
self.view = myView;
[myView release];
CGRect rectangle = CGRectMake(20, 20, 20, 20);
[self.view drawRect:rectangle];
}
I couldn't make your drawing code work, I don't know much about that.
One way to avoid the cast would be to add a separate outlet property for the custom view on the controller, and refer to that instead.
In Interface Builder, make an instance of MyCustomView and drag it into the existing view to make it a subview, then attach it to its own outlet on the controller.
I'm following iPhone dev courses from Stanford Open-University, and I've been blocked for 2 days on assignment3, maybe someone can help me here?
The tasks are:
Create a custom UIView subclass that will display your PolygonShape object
Give your view class access to the PolygonShape object so that it can retrieve the details of the polygon as needed
The problem is: how do I give my view class access to the polygon object defined in my controller?
Here is my implementations if it can help:
CustomView.h:
#import "PolygonShape.h"
#interface CustomView : UIView {
IBOutlet PolygonShape *polygon;
}
- (NSArray *)pointsForPolygonInRect:(CGRect)rect numberOfSides:(int)numberOfSides;
#end
Controller.h:
#import <UIKit/UIKit.h>
#import <Foundation/Foundation.h>
#import "PolygonShape.h"
#import "PolygonView.h"
#interface Controller : NSObject {
IBOutlet UIButton *decreaseButton;
IBOutlet UIButton *increaseButton;
IBOutlet UILabel *numberOfSidesLabel;
IBOutlet PolygonShape *polygon;
IBOutlet PolygonView *polygonView;
}
- (IBAction)decrease;
- (IBAction)increase;
- (void)awakeFromNib;
- (void)updateInterface;
#end
And after you figure it out, it might not hurt to touch up on some objective-c basics:
http://www.cocoacast.com/?q=node/103
Found my own answer, I missed a setPolygon method in my CustomView to link both... stupid...
in CustomView.h:
#import "PolygonShape.h"
#interface CustomView : UIView {
IBOutlet PolygonShape *polygon;
}
#property (readwrite, assign) PolygonShape *polygon;
- (NSArray *)pointsForPolygonInRect:(CGRect)rect numberOfSides:(int)numberOfSides;
#end
in CustomView.m:
#implementation CustomView
#synthesize polygon;
...
#end
in Controller.m:
- (void)awakeFromNib {
// configure your polygon here
polygon = [[PolygonShape alloc] initWithNumberOfSides:numberOfSidesLabel.text.integerValue minimumNumberOfSides:3 maximumNumberOfSides:12];
[polygonView setPolygon:polygon];
NSLog (#"My polygon: %#", [polygon description]);
}
I just finished assignement 3 last night. I solved this connection all in Interface Builder. First I created an outlet on the "PolygonView" UIView subclass for the PolygonShape and then connected it to the instance of the Polygon model. From what I have read in the Google Group and on various other sites, I do not think there is one right way to connect this UIView to the model and the controller. But it worked I think there is nothing wrong with the View knowing about the model.
So why aren't you declaring them as properties of the class?