最上级vc里面加 下级设置生效
UIImage* image = [UIImage imageNamed:@"back_button.png"]; [item setBackButtonBackgroundImage:[image resizableImageWithCapInsets:UIEdgeInsetsMake(0, image.size.width, 0, 0)] forState:UIControlStateNormal barMetrics:UIBarMetricsDefault]; [item setBackButtonTitlePositionAdjustment:UIOffsetMake(-400.f, 0) forBarMetrics:UIBarMetricsDefault]; self.navigationItem.backBarButtonItem = item;