Chapter 3

tamcakes · January 28th, 2011, 11:06 PM

I got the first example working once, but for whatever reason, when I try to do it again it doesn't work. Can you tell me where I'm going wrong? The button just isn't popping up.

Working version:

Quote:

H file

//
// outlets_and_actionsViewController.h
// outlets and actions
//
// Created by Tam Hartman on 1/27/11.
// Copyright 2011 __MyCompanyName__. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface outlets_and_actionsViewController : UIViewController {

//--declaring the outlet --
IBOutlet UITextField *txtName;
}

//--expose the outlet as a property --
@property (nonatomic, retain) UITextField *txtName;

//---declaring the action---
-(IBAction) btnClicked:(id) sender;

@end

Quote:

M FILE
#import "outlets_and_actionsViewController.h"

@implementation outlets_and_actionsViewController

//-synthesize the property-
@synthesize txtName;

//---displays an alert view when the button is clicked---
-(IBAction) btnClicked:(id) sender {
NSString *str = [[NSString alloc]
initWithFormat:@"Hello, %@", txtName.text];
UIAlertView *alert = [[UIAlertView alloc]
initWithTitle:@"Are you a Cylon?"
message:str
delegate:self
cancelButtonTitle:@"I'm A Frakin Cylon!"
otherButtonTitles:nil];
[alert show];
[str release];
[alert release];
}

-(void)dealloc{
//release the outlet
[txtName release];
[super dealloc];
}

and here's what isn't working:

Quote:

M file

#import "outlets_and_actions_2ViewController.h"

@implementation outlets_and_actions_2ViewController

//-synthesize the property
@synthesize txtName;

//displays an alert view when the button is clicked
-(IBAction) btnClicked:(id) sender {
NSString *str = [[NSString alloc]
initWithFormat:@"Hello, %@", txtName.text];
UIAlertView *alert = [[UIAlertView alloc]
initWithTitle:@"Hello"
message:str
delegate:self
cancelButtonTitle:@"Done"
otherButtonTitles:nil];
[alert show];
[str release];
[alert release];
}

-(void)dealloc{
//release the outlet
[txtName release];
[super dealloc];
}

Quote:

h file
//
// outlets_and_actions_2ViewController.h
// outlets and actions 2
//
// Created by Tam Hartman on 1/28/11.
// Copyright 2011 __MyCompanyName__. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface outlets_and_actions_2ViewController : UIViewController {

//declaring the outlet
IBOutlet UITextField *txtName;
}

//expose the outlet as a property
@property (nonatomic, retain) UITextField *txtName;

//declaring the action
-(IBAction) btnClicked:(id) sender;

@end

maybe someone will see something that I'm not?

thepianoguy · January 28th, 2011, 11:33 PM

Check that you connected and SAVED your outlets and actions in Interface Builder. The code is fine.
Bob

tamcakes · January 28th, 2011, 11:35 PM

Quote:

Originally Posted by thepianoguy

Check that you connected and SAVED your outlets and actions in Interface Builder. The code is fine.
Bob

done and done. still not working.

thepianoguy · January 28th, 2011, 11:39 PM

The code looked fine, I set up the project and did a copy and paste of your code into the .h and .m files and it worked as expected
If you want send your non-working project files to
ipadhelper@me.com
and I'll take a quick look at it for you.

tamcakes · January 28th, 2011, 11:42 PM

Quote:

Originally Posted by thepianoguy

The code looked fine, I set up the project and did a copy and paste of your code into the .h and .m files and it worked as expected
If you want send your non-working project files to
ipadhelper@me.com
and I'll take a quick look at it for you.

sent. Thank you :)

thepianoguy · January 29th, 2011, 08:33 AM

Happy to help.

milpitian · February 6th, 2011, 12:08 AM

//
// OutletsAndActionsViewController.m
// OutletsAndActions
//
// Created by Dean on 2/5/11.
// Copyright 2011 __MyCompanyName__. All rights reserved.
//

#import "OutletsAndActionsViewController.h"

@implementation OutletsAndActionsViewController

//---synthesize the property---
@synthesize txtName;

//---displays an alert view when the button is clicked---
-(IBAction) btnClicked:(id) sender {
NSString *str = [[NSString alloc]
initWithFormat:@"Hello, %@", txtName.text];
message:str
delegate:self (error saids "expected before delegate"
cancelButtonTitle:@"Done"
[otherButtonTitles:nil];
[alert show];(error here saids "alert undeclared first use in this action")
[str release];
[alert release];
}
/*
// The designated initializer. Override to perform setup that is required before the view is loaded.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
*/

/*
// Implement loadView to create a view hierarchy programmatically, without using a nib.
- (void)loadView {
}
*/

/*
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
[super viewDidLoad];
}
*/

/*
// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIIn terfaceOrientation)interfaceOrientation {
// Return YES for supported orientations
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
*/

- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];

// Release any cached data, images, etc that aren't in use.
}

- (void)viewDidUnload {
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}

- (void)dealloc {
//--release the outlet---
[txtName release];
[super dealloc];
}

@end

thepianoguy · February 6th, 2011, 08:22 AM

Based on the code you have provided, you are missing a line. No UIAlertView is defined or allocated, and part of the initialization is missing.
The missing line is in bold

Code:

	
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Hello!"
													message:str
												   delegate:self
										  cancelButtonTitle:@"Done"
										  otherButtonTitles:nil];

milpitian · February 6th, 2011, 12:36 PM

ahhh, thanks piano guy. it launched ok now.