按下 UIBarButtonItem 时应用程序崩溃

Question

My app crashes when I tap on an UIBarButtonItem. I tried many different ways to write the function that will be called but could not find the solution so far. My code is below. Thank you for your help!

#import <Foundation/Foundation.h>
#include<pthread.h>

#import <Contacts/Contacts.h>
#import <ContactsUI/ContactsUI.h>
#import <ContactsUI/CNContactViewController.h>
#import <UIKit/UIKit.h>

@interface AddressBookAccess:UIViewController
@end

@implementation AddressBookAccess:UIViewController


+(BOOL)AddNewContact
{
// Removing code here

    newNavigationController.navigationBar.topItem.leftBarButtonItem = [[UIBarButtonItem alloc]initWithTitle:@"Back to AReach" style:UIBarButtonItemStylePlain target:self action:@selector(pressButton:)];

    [viewController presentViewController:newNavigationController animated:YES completion:nil];
    return YES;
}

-(IBAction)pressButton:(UIBarButtonItem*)btn
{
    NSLog(@"button tapped %@", btn.title);
}

@end

Answer 1

Dan. I noticed that you added a button to the class method and bound the event, where self refers to the current class, then the button should bound to a class method.

Now the button method you provide is an instance method, so you will get an error like this. +[AddressBookAccess pressButton:]: unrecognized selector sent to class 0x104d2dac8

Since you noticed that your event is associated with the storyboard, I suggest you create a button in the instance method and bind the event.