导航栏后退按钮不起作用

Question

I am trying add a custom back button so that I can perform some tasks before popping the controller. But no matter how hard I tried this function bind with back button doesn't work. I am adding some code to understand

-(void)customizeNavigationBar
{
    self.navigationController.navigationBarHidden = NO;
    self.navigationItem.title = @"Video Call";

   UIBarButtonItem *backButton = [[UIBarButtonItem alloc] 
              initWithTitle:@" " style:UIBarButtonItemStylePlain 
              target:self action:@selector(didBackBtnTap)];
   [self.navigationItem setBackBarButtonItem:backButton];
}

and this is the function, which is not calling at all,

-(void)didBackBtnTap
{
    [self popToProfileScreen];
}

Please suggest any solution, Thanks in advance.

Answer 1

使用leftbarbutton项而不是setBackBarButtonItem

self.navigationItem.leftBarButtonItem = backButton;

Answer 2

When you use the setLeftBarButtonItem or setBackBarButtonItem , it will take effect on the viewController you're pushing to but not the current one. That's why you need to directly set the current leftBarButtonItem

Answer 3

另一个选择是在viewWillDisappear中编写您的自定义代码。

Answer 4

Use this code

UIButton *backButton = [UIButton buttonWithType:UIButtonTypeCustom];
backButton.frame = CGRectMake(0, 0, 15, 15);
[backButton setImage:[UIImage imageNamed:@"backButtonImage"] forState:UIControlStateNormal];
[backButton setTitle:@"Back" forState:UIControlStateNormal];
backButton.imageEdgeInsets = UIEdgeInsetsMake(0, -10, 0, 0);
[backButton addTarget:self action:@selector(backButtonPressed) forControlEvents:UIControlEventTouchUpInside];
self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:backButton];

Add an image(15*15, @1x @2x @3x) like back button of NavigationBar in xcasstes backButtonImage

- (void)backButtonPressed {}