Using variable value from another class Objective-c - objective-c

Question

I know this has been posted many times but I cannot get it to work, there are no errors in my code (found by Xcode), but what I'm trying to do isn't working.
1- Setup: I have 2 classes, ViewController (UIViewController) and GraphView (UIView)
2- What I am trying to do: I have a BOOL type variable plotPressedVC in ViewController that takes an initial value NO.
Once a button is pressed (this IBAction is located in the ViewController.m file) plotPressedVC = YES. From this, in my GraphView.m file I have an if statement whose condition is met if pressed = YES.
3- My code:
ViewController.h
#import <UIKit/UIKit.h>
#interface ViewController : UIViewController {
#public BOOL plotPressedVC;
}
- (IBAction)plot:(id)sender;
#end
ViewController.h
#import "ViewController.h"
#import "GraphView.h"
#implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
plotPressedVC = YES;
}
- (IBAction)plot:(id)sender {
plotPressedVC = YES;
GraphView *plotPress = [[GraphView alloc] init];
plotPress.plotPressed = plotPressedVC;
}
#end
GraphView.h
#import <UIKit/UIKit.h>
#interface GraphView : UIView {
BOOL plotPressed;
}
#property (nonatomic) BOOL plotPressed;
#end
GraphView.m
#import "GraphView.h"
#import "ViewController.h"
#implementation GraphView
- (void)drawLineGraphWithContext:(CGContextRef)ctx {
if (plotPressed == YES) {
NSLog(#"yep");
}
// Other code that I want to be in if statement
}
#end
4- Question: What have I done wrong for the if statement's condition to not have been met when pushing the button plot?
EDIT: added NSlog at the end of the plot action, I am getting values 80, -64, -128...
- (IBAction)plot:(id)sender {
plotPressedVC = YES;
NSLog(#"%hhd",plotPressedVC);
GraphView *plotPress = [[GraphView alloc] init];
plotPress.plotPressed = plotPressedVC;
NSLog(#"%hhd",plotPress);
}
New Question: How come plotPress is receiving other numbers than 0 or 1?

Answer 1

It's been asked many times and it usually has the same answer.
The problem is here:
GraphView *plotPress = [[GraphView alloc] init];
plotPress.plotPressed = plotPressedVC;
Here you create a new graph view, set the value on it, and then do nothing else with it. You need to have an outlet or property to the existing graph view and set the plotPressed value on that.
Currently that graph view is never added to another view, and under ARC will be immediately deallocated at the end of the method.