UILabel Text does not update - objective-c

Question

The main view has a label and a button. I added one subview which contain a UILabel and a button. What I want to do is that I want to update two labels at the both view by pressing one of two button.
The problem is, if I click the button of the subview, the label of the subview is only updated. Conversely, the label of the main view is only changed when I click the button in the main view.
I am wondering how to update each label.text of the other view.
Thanks in advance...
Here is my code.
1. ViewController.h
#import <UIKit/UIKit.h>
#import "SubView.h"
#interface ViewController : UIViewController{
SubView *subView;
}
#property (weak, nonatomic) SubView *subView;
#property (retain, nonatomic) IBOutlet UILabel *amount;
#end
2. ViewController.m
#import "ViewController.h"
#import "SubView.h"
#interface ViewController ()
#end
#implementation ViewController
#synthesize subView=_subView;
#synthesize amount;
- (void)viewDidLoad
{
[super viewDidLoad];
subView = [[SubView alloc]initWithFrame:CGRectMake(10, 10, 300, 600)];
[self.view addSubview:subView];
amount = [[UILabel alloc]initWithFrame:CGRectMake(400, 400, 100, 50)];
amount.text = #"test in the main view";
[self.view addSubview:amount];
UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
btn.frame = CGRectMake(400, 300, 40, 20);
btn.backgroundColor = [UIColor clearColor];
[btn addTarget:self action:#selector(labelChange:)
forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:btn]; // add a button in the main view
// Do any additional setup after loading the view, typically from a nib.
}
- (IBAction)labelChange:(id)sender{
amount.text = #"defaul label";
SubView *sv = [[SubView alloc]init];
sv.addObject2.text = #"label in the subview";
NSLog(#"sv.addObject2.text = %#",sv.addObject2);
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return YES;
}
#end
3. SubView.h
#import <UIKit/UIKit.h>
#interface SubView : UIView {
UIButton *btn;
UILabel *label;
}
//#property (strong, nonatomic) UIView *view;
#property (weak, nonatomic) UIButton *btn;
#property (weak, nonatomic) UILabel *label;
- (UIButton *)addObject1;
- (UILabel *)addObject2;
#end
4. SubView.m
#import "SubView.h"
#import "ViewController.h"
#implementation SubView
#synthesize btn=_btn, label=_label;
//#synthesize view;
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
//UIView *contentView = [[UIView alloc]initWithFrame:frame];
self.backgroundColor = [UIColor blackColor];
UIButton *object1 = [self addObject1];
UILabel *object2 = [self addObject2];
[self addSubview:object1];
[self addSubview:object2];
return self;
}
- (UIButton *)addObject1{
btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
btn.frame = CGRectMake(10, 10, 100, 20);
btn.backgroundColor = [UIColor clearColor];
[btn addTarget:self action:#selector(labelChange:) forControlEvents:UIControlEventTouchUpInside];
return btn;
}
- (IBAction)labelChange:(id)sender{
label.text = #"change the label in the subview";
ViewController *vc = [[ViewController alloc]init];
[vc.amount setText:#"change the label in the mainview"];
}
- (UILabel *)addObject2{
label = [[UILabel alloc]initWithFrame:CGRectMake(10, 50, 200, 50)];
[label setText: #"default"];
label.backgroundColor = [UIColor clearColor];
label.font = [UIFont fontWithName:#"Arial" size:12];
label.textColor = [UIColor whiteColor];
return label;
}
#end

Answer 1

I think u need to read "The Objective-C Programming Language" and know how the "Object" and "Pointer" means
Here is the code
SubView.h
#import <UIKit/UIKit.h>
#interface SubView : UIView {
UIButton *btn;
UILabel *label;
}
#property (weak, nonatomic) UIViewController *vc;
#property (weak, nonatomic) UIButton *btn;
#property (weak, nonatomic) UILabel *label;
- (UIButton *)addObject1;
- (UILabel *)addObject2;
#end
Subview.m
#import "SubView.h"
#import "ViewController.h"
#implementation SubView
#synthesize btn=_btn, label=_label;
#synthesize vc;
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
self.backgroundColor = [UIColor blackColor];
UIButton *object1 = [self addObject1];
UILabel *object2 = [self addObject2];
[self addSubview:object1];
[self addSubview:object2];
return self;
}
- (UIButton *)addObject1{
btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
btn.frame = CGRectMake(10, 10, 100, 20);
btn.backgroundColor = [UIColor clearColor];
[btn addTarget:self action:#selector(labelChange:) forControlEvents:UIControlEventTouchUpInside];
return btn;
}
- (IBAction)labelChange:(id)sender{
label.text = #"change the label in the subview";
[vc.amount setText:#"change the label in the mainview"];
}
- (UILabel *)addObject2{
label = [[UILabel alloc]initWithFrame:CGRectMake(10, 50, 200, 50)];
[label setText: #"default"];
label.backgroundColor = [UIColor clearColor];
label.font = [UIFont fontWithName:#"Arial" size:12];
label.textColor = [UIColor whiteColor];
return label;
}
#end
ViewController.m
#import "ViewController.h"
#import "SubView.h"
#interface ViewController ()
#end
#implementation ViewController
#synthesize subView=_subView;
#synthesize amount;
- (void)viewDidLoad
{
[super viewDidLoad];
subView = [[SubView alloc]initWithFrame:CGRectMake(10, 10, 300, 600)];
subView.vc = self;
[self.view addSubview:subView];
amount = [[UILabel alloc]initWithFrame:CGRectMake(400, 400, 100, 50)];
amount.text = #"test in the main view";
[self.view addSubview:amount];
UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
btn.frame = CGRectMake(400, 300, 40, 20);
btn.backgroundColor = [UIColor clearColor];
[btn addTarget:self action:#selector(labelChange:)
forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:btn]; // add a button in the main view
}
- (IBAction)labelChange:(id)sender{
amount.text = #"defaul label";
subview.addObject2.text = #"label in the subview";
}
#end

Answer 2

I think I got what you are trying to do and here is what you should do:
1- Create 3 new files (xib,m,h) call them SubView.xib,m,h. You have to make sure it inherits UIView.
2- in the xib file draw the subview elements and hook the IBOutlets with it. But make sure that the file owner is the ViewController and the root view class type is "SubView"
3- Make an IBOutlet of type Subview in ViewController
4- open SubView.xib and hook the SubView (the root node in the objects tree) with the File Owner IBOutlet you made # step 3
to load the new SubView in the ViewController.m simply call this line:
after that line your IBOutlet in ViewController will have the object of SubView.
[[NSBundle mainBundle] loadNibNamed:#"SubView" owner:self options:nil];
in the above code self is reflected to the ViewController