节目接收信号EXC_BAD_ACCESS

Question

When i click on done button which has code

UIBarButtonItem * button = [[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone
                                                                          target:self
                                                                         action:@selector(dismissView:)] autorelease];

self.navigationItem.rightBarButtonItem=UIBarButtonSystemItemDone;
[[self navigationItem] setRightBarButtonItem:button];
[button release];

-(void)dismissView: (id)sender

{

[self.navigationController popToRootViewControllerAnimated:YES];

}

application crashes and gives message Program received signal EXC_BAD_ACCESS

Any ideas what is wrong.

Thanks for help.

Answer 1

This line is entirely wrong:

self.navigationItem.rightBarButtonItem=UIBarButtonSystemItemDone;

Remove it. You are setting the rightBarButtonItem right after that and also, you can't set the rightBarButtonItem to UIBarButtonSystemItemDone - that just doesn't make any sense at all.

Oh and you're overreleasing button . Remove the [button release]; as well.

Answer 2

You are over-releasing your button. You autorelease it when you alloc/init and then release it again after setting it as the nav item.

Answer 3

You're over-releasing button . Its +alloc call on the first line is already balanced by the -autorelease on that same line—you don't need to call -release on it thereafter.