监听返回

popViewController回调用dealloc

- (void)dealloc { NSLog(@"123"); }

viewWillDisappear将要消失

- (void)viewWillDisappear:(BOOL)animated{ if ([self.navigationController.viewControllers indexOfObject:self]==NSNotFound) { NSLog(@"clicked navigationbar back button"); } }

重写leftbarItem

self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"back_icons"] style:UIBarButtonItemStylePlain target:self action:@selector(onBack)];