在扩展类里面:
@implementation UIViewController (BackNavigationBar)
-(void)awakeFromNib{
[super awakeFromNib];
self.navigationItem.leftBarButtonItem = [self backButton];
NSLog(@"test test:%f",self.navigationItem.leftBarButtonItem.customView.frame.origin.x);
}
- (UIBarButtonItem *)backButton
{
UIBarButtonItem * item = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"ic_back" ] style:UIBarButtonItemStylePlain target:self action:@selector(backButtonPressed)];
return item;
}
-(void)backButtonPressed{
[self.navigationController popViewControllerAnimated:YES];
}
@end
注意,如果自定义按钮的图片变形,可能是使用的图片尺寸问题