objective-C : @synthesize not working and basic operations not working :*(

Question

I am unsure why this code will not work and what i want it to do is when i click a button(action: buttonclick) i want it to change the two text box's(MyTextLabel & MyTextLabel2) text increment the value "r" by one. here is the code:

MainView.h


#import <UIKit/UIKit.h>
#import <Foundation/Foundation.h>

@interface MainView : UIView {
    IBOutlet UIButton *MyButton;
    IBOutlet UILabel *MyTextLabel;
    IBOutlet UILabel *MyTextLabel2;

}

@property (nonatomic, retain) UIButton *MyButton;
@property (nonatomic, retain) UILabel *MyTextLabel;
@property (nonatomic, retain) UILabel *MyTextLabel2;


- (IBAction)buttonclick;
@end

MainView.m:

#import "MainView.h"
#include <stdlib.h>
#include <libc.h>


@implementation MainView

@synthesize MyButton, MyTextLabel, MyTextLabel2;

int r;  


- (IBAction)buttonclick {

    r++

 if(r < 50) {

  MyTextLabel.text = @"< 50";
 } else {
  MyTextLabel2.text = @"=> 50";
 }

}
@end

Answer 1

You don't say in your question what, exactly, isn't working the way you expect it. My guess is going to be that your outlets aren't actually connected properly. You might want to add a log statement to buttonClick like this:

NSLog(@"button click called! MyTextLabel is %@", MyTextLabel);

The point being, mostly, to be sure it isn't nil.

Answer 2

I have a feeling something's wrong with the way you're using int r. Try putting static int r; at the top of the @interface line in MainView.h and also add, under the - (IBAction)buttonclick; line:

+(void) initialize;

Then remove int r; from MainView.m. Then in MainView.m add:

+(void) initialize {
   count = 0;
}

Answer 3

I see two issues:

1. You can't declare int r where you have it. You should declare it in your interface's variable block (where you declare your button and labels or outside a method) or in the method definition.
2. The line with r++ isn't ended with a semi-colon.

Answer 4

In Objective-c the names of variables and properties must start with a lowercase letter to conform to the Key-Value Coding (KVC) protocol (always myButton, never MyButton). The @synthesize directive relies on this to generate the setters and getters. Thus, for myButton @synthesize will generate -(void)setMyButton:(UIButton *)button and -(UIButton *)myButton. So, lowercase MyButton and its colleagues and see if it helps.