Pass an argument to selector

Question

I have a UIButton inside my custom cell and I want to trigger an action when the user presses that button BUT I need to know from which row the UIButton was pressed.

Here is my code:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell"];
    [self configureCell:cell atIndexPath:indexPath];
    return cell;

    ...

    [button addTarget:self action:@selector(buttonPressedAction:)forControlEvents:UIControlEventTouchUpInside];

}

- (void)buttonPressedAction:(UIButton *)button
{
    //int row = indexPath.row;
    //NSLog(@"ROW: %i",row);
}

How do I pass the indexPath as argument to my selector?

http://stackoverflow.com/questions/7504421/getting-row-of-uitableview-cell-on-button-press/7505025#7505025 — user523234, Sep 06 '12 at 10:05

score 6 · Accepted Answer · answered Sep 06 '12 at 10:03

6

You can either set the tag property of the button to the row number:

button.tag = indexPath.row;

and retrieve it using

NSInteger row = button.tag;

or set the index path object itself as an associated object to the button:

objc_setAssociatedObject(button, "IndexPath", indexPath);

and

NSIndexPath *ip = objc_getAssociatedObject(button, "IndexPath");

answered Sep 06 '12 at 10:03

Thanks! The associated object to the button looks like an elegant solution – Pupillam Sep 06 '12 at 10:17
@Prince exactly as I wrote in the example. – Sep 06 '12 at 11:00
its giving warning implicit declaration of 'objc_setAssociatedObject'. As i need to ignore warning, i m using xcode 4.4.1 – Paresh Navadiya Sep 06 '12 at 11:21
solved by #import . Thanks @H2CO3 wonderful answer – Paresh Navadiya Sep 06 '12 at 12:14
if i can use the method to pass a nsobject for example naaarray or custom object as People? – pengwang Apr 14 '13 at 13:01

Anshuk Garg · Answer 2 · 2012-09-06T10:23:43.797

2

while adding the button on the custom cell, u can add the tag property of UIButton as

UIButton *sampleButton = [[UIButton alloc] init];
sampleButton.tag = indexPath.row;

and then when u call, u can check the tag

- (void)buttonPressedAction:(UIButton*)sender
{
    if(sender.tag==0)
    {
      //perform action
    }
}

hope it helps. happy coding :)

edited Sep 06 '12 at 10:23

answered Sep 06 '12 at 10:04

Anshuk Garg

1,540
12
14

You have to declare the button as UIButton, else the property accessor won't work. (I didn't -1, btw). – Sep 06 '12 at 10:07

score 1 · Answer 3 · edited Mar 18 '16 at 11:32

Simple set the button tag ..

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell"];
    [self configureCell:cell atIndexPath:indexPath];
    return cell;

    ...

    [button setTag = indexPath.row]; // Set button tag

    [button addTarget:self action:@selector(buttonPressedAction:)
                                            forControlEvents:UIControlEventTouchUpInside];
    }

    - (void)buttonPressedAction:(id)sender
    {
        UIButton *button = (UIButton *)sender;
        int row = [button superview].tag;
    }
}

score 1 · Answer 4 · answered Sep 07 '12 at 18:32

Its even simple than setting a tag. Try this..

To get The indexPath try the following code.

UIView *contentView = (UIVIew *)[button superview];
UITableViewCell *cell = (UITableViewCell *)[contentView superview];
NSIndexPath *indexPath = [self.tableview indexPathForCell:cell];

OR

NSIndexPath *indexPath = [self.tableview indexPathForCell:(UITableViewCell *)[(UIVIew *)[button superview] superview]];

Pass an argument to selector

4 Answers4

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