UIButton from my class not working (EXC_BAD_ACCESS) in ViewController - ios

Question

I made my own class with the UIView including the UIButton and the method for it:
MyClass.h
#property (strong, nonatomic) UIView* mainBack;
#property (strong, nonatomic) UIButton* sortButton;
MyClass.m
- (id) initFor: (int) object {
if (self = [super init]) {
_mainBack = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 50)];
_sortButton = [UIButton buttonWithType:UIButtonTypeSystem];
_sortButton.frame = CGRectMake(10.0, 5.0, 60.0, 40.0);
[_sortButton addTarget:self action:#selector(ChangeSort) forControlEvents:UIControlEventTouchUpInside];
[_mainBack addSubview:_sortButton];
}
return self;
}
- (void) ChangeSort {
NSLog(#"change");
}
- (void) ShowBarOnView: (UIViewController*) view AtPoint: (CGPoint) point{
[_mainBack setFrame:CGRectMake(point.x, point.y, _mainBack.frame.size.width, _mainBack.frame.size.height)];
[view.view addSubview:_mainBack];
}
In ViewController I made the instance of myClass and called the method to show view
MyClass* mySort = [[myClass alloc] initFor: rooms];
[mySort ShowBarOnView:self AtPoint:CGPointMake(0, 50)];
So, I got the view with the button, but when pressed, the application crashes and shows:
EXC_BAD_ACCESS (code=1, address=0x0)
What is wrong?
Thanks.

Answer 1

Yes, I had the Same Problem!
I had my MainViewController creating the PlayingViewController in a method and long story short that was the problem.
SOFMainVC.h
SOFMainVC.m
#import "SOFPlayingVC.h" ...
- (void)someMethodBeingCalled {
SOFPlayingVC *playingVC = [[SOFPlayingVC alloc] init];
[self.view addSubview:playingVC.view];
}
SOFPlayingVC.m
...
...
- (void)viewDidLoad {
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setFrame:CGRectMake(0, 0, 100, 50)];
[button addTarget:self
action:#selector(buttonAction:)
forControlEvents:UIControlEventTouchUpInside];
[self.view addSubView:button];
...
...
}
And if we were to Focus on SOFPlayingVC in instruments we'll see that the controller will be garbage collected as soon as it's done being instantiated. However if we simply add it to the controller that is in use as a #property (nonatomic, strong) we wont lose it until its out of the SOFMainViewController.
So the Solution to our issue here was to:
#import "SOFPlayingVC.h"
SOFMainVC.h
...
#interface SOFMainVC : UIViewController
#property (nonatomic, strong) SOFPlayingVC *playingVC;
...
#end
SOFMainVC.m
#import "SOFPlayingVC.h" ... ...
- (void)someMethodBeingCalled {
SOFPlayingVC *playingViewController = [[SOFPlayingVC alloc] init];
[self.view addSubview:playingVC.view];
}

Answer 2

If the posted code snippet appears exactly as written, the problem is that the following lines are NEVER executed. Xcode should probably be warning you about them:
_mainBack = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 50)];
_sortButton = [UIButton buttonWithType:UIButtonTypeSystem];
_sortButton.frame = CGRectMake(10.0, 5.0, 60.0, 40.0);
[_sortButton addTarget:self action:#selector(ChangeSort)
forControlEvents:UIControlEventTouchUpInside];
[_mainBack addSubview:_sortButton];
As posted, these lines exist completely outside of any method. What would make most sense is to create a factory method:
+ (instancetype) mainViewAtPoint:(CGPoint)point inContext:
(UIViewController*)viewController {
self.mainBack = [[UIView alloc] initWithFrame:CGRectMake(point.x,point.y,
320,50)];
self.sortButton = [UIButton buttonWithType:UIButtonTypeSystem];
self.sortButton.frame = (CGRectMake(10.0, 5.0, 60.0, 40.0);
[self.sortButton addTarget:self action:#selector(ChangeSort)
forControlEvents:UIControlEventTouchUpInside];
[self.mainBack addSubview:self.sortButton];
[viewController.view addSubview: self.mainBack];
}
Now all you have to do to alloc, init, create, and add this view to your view controller is simple this:
[myClass mainViewAtPoint:aPoint inContext:aViewController];
The obvious clue that your button isn't actually created is tipped off by the EXC_BAD_ACCESS. It's telling you it's trying to reference memory location 0x0. Any time anything is trying to access 0x0 memory address, you're trying to call a method on an object that doesn't have a memory address... it's never been alloc'ed.

Answer 3

I solved this problem, by adding in
in ViewController.h
#property (strong, nonatomic) MyClass* mySort;
and changing my code in ViewController.m to
_mySort = [[SortAndSeach alloc] initFor:for_what];
[_mySort ShowBarOnView:self AtPoint:CGPointMake(0, 50)];
Thanks to all!