objective c - iOS - passing arguments in action:@selector()

Question

I'm adding a button to a UITableViewCell programmatically. The method to be run when the button is pressed is - (void) quantityDown:(id)sender rowNumber:(int)rowNum, where rowNum is the row that the button appears in.

When adding the target to the button, Xcode autocompletes the following:

[buttonDown addTarget:self action:@selector(quantityDown:rowNumber:) forControlEvents:UIControlEventTouchUpInside];

But no matter what I try, I cannot pass the row number into the method. I assumed the pertinent portion of code would look like

action:@selector(quantityDown:rowNumber:indexPath.row)

but that doesn't do the trick. I've seen other stuff like

action:@selector(quantityDown:)rowNumber:indexPath.row

and

action:@selector(quantityDown:rowNumber:)withObject:@"first" withObject:@"Second"

But neither work. I don't need to pass a first argument, just the row number. I've also tried defining the method like - (void) quantityDown:(int)rowNum and then writing the selector like:

action:@selector(quantityDown:indexPath.row)

but that also doesn't work.

Thoughts?

Thanks in advance.

Answer 1

Why don't you make a Custom UIButton class and have the object as property?

See below.

"MyButton.h"

@interface MyButton : UIButton
@property(nonatomic, strong)MyClass *obj;
@end

"MyButton.m"

#import "MyButton.h"

@implementation MyButton

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
    }
    return self;
}

@end

Now assign MyButton class to your actual button in the cell/ or initialize the custom button instead of normal UIButton class and assign the object directly.

And in your IBAction where sender=MyButton

- (void) quantityDown:(id)sender{
   MyButton *btn  = (MyButton *)sender;
   //You get the object directly
   btn.obj;
}

Doing it this way you can actually access as many properties you want easily. And its useful in other implementations too.

Hope it helps.