Custom setter not getting called in UIView

Question

I am using a custom setter for a bool property as I need to do some extra work when this value changes. Here is my implementation:

MyView.h

@interface MyView : UIView 

@property (nonatomic) BOOL isSelected;

@end

MyView.m

@implementation MyView

@synthesize isSelected;

-(void)setIsSelected:(BOOL)_isSelected
{
    self.isSelected = _isSelected;

    //Custom code that changes UI based on bool state  


}

@end

However the setter is not getting called! Can someone tell me why?

Answer 1

Two ways to set your property and your setter method get called.

1、Dot Syntax : self.isSelected = YES ; 2、call it directly. [set setIsSelected:YES] ;

@interface MyView : UIView 
@property (nonatomic) BOOL isSelected;
@end

@implementation MyView
@synthesize isSelected;
-(void)setIsSelected:(BOOL)_isSelected
{
    isSelected = _isSelected;
    //Custom code that changes UI based on bool state  
}
@end

Your app crash because you call self.isSelected = _isSelected in your setter method, it will call your setter method recursively and endlessly until the stack over flow !

Answer 2

e.g. in viewDidLoad set value self.isSelected=YES;, or where you want to set this value.

Your setter method should looks like:

-(void)setIsSelected:(BOOL)seleted
{
    _isSelected = seleted;

    //Custom code that changes UI based on bool state


}

This is "setter cycle" if you in setter use that code: self.isSelected = _isSelected;

Answer 3

Try this,

   //in myView.h
   @interface customView : UIView
  {

  }
  @property(nonatomic)BOOL *isSelected;
  @end

in myView.m file

    @implementation customView
    @synthesize isSelected = _isSelected;


    - (void)setIsSelected:(BOOL *)inSelected //inSelected is the in coming value for bool
    {
       _isSelected = inSelected;
       NSLog(@"setter is called");
    }

Answer 4

Try changing the -(void)setIsSelected: method's argument _isSelected to some other variable say selected and use it to assign the property as _isSelected = selected; in the method.

Answer 5

In some cases, when your object is nil it will give you the sense that setter and getter are not called. Hopefully you solve the problem.