Pressing UIButton results in Unrecognized Selector

Question

I have a button in my UIView that is created like so:

UIBarButtonItem *editButton = 
        [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemEdit 
                                                      target:self       
                                                      action:@selector(toggleEdit)];
self.navigationItem.rightBarButtonItem = editButton;
[editButton release];

And this is the action method:

-(void) toggleEdit:(id)sender
{
}

but I get this error

2011-09-02 15:27:13.362 blubb[15006:207] -[DatabaseSelectionViewController toggleEdit]: unrecognized selector sent to instance 0x5a29d80 2011-09-02 15:27:13.365 blubb[15006:207] * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[DatabaseSelectionViewController toggleEdit]: unrecognized selector sent to instance 0x5a29d80'

Why is this happening?

Answer 1

Try:

UIBarButtonItem *editButton = [[UIBarButtonItem alloc]
initWithBarButtonSystemItem:UIBarButtonSystemItemEdit
target:self action:@selector(toggleEdit) forControlEvents:UIControlEventTouchUpInside];

Answer 2

The correct name for your selector is

@selector(toggleEdit:)

Without the : it would look for a method with this signature:

-(void) toggleEdit  // No parameters
{
}

When you actually have declared:

-(void) toggleEdit:(id)sender
{
}

Answer 3

If you are using a storyboard. Sometimes it helps to remove the button from the storyboard, and put a new button, and make the necessary connections.

Answer 4

should be:

-(IBAction) toggleEdit:(id)sender {}

and

@selector(toggleEdit:)

Answer 5

The method you're trying to use takes an argument, which means that it has a colon in its name -- the colon is actually part of the name. You need to include that colon when you get the selector:

@selector(toggleEdit:)

Refer to the Message Syntax section of The Objective-C Programming Language:

A selector name includes all the parts of the name, including the colons, so the selector in the preceding example is named setOriginX:y:. It has two colons, because it takes two parameters. The selector name does not, however, include anything else, such as return type or parameter types.

Answer 6

Change

@selector(toggleEdit)

to

@selector(toggleEdit:)