隱藏導航控制器下面的線

viewDidLoad
//隱藏導航控制器下面的線
-(void)deleteNavigationLine {
        if ([self.navigationController.navigationBar respondsToSelector:@selector( setBackgroundImage:forBarMetrics:)]){
       
        NSArray *list=self.navigationController.navigationBar.subviews;
       
        for (id obj in list) {
           
            if ([obj isKindOfClass:[UIImageView class]]) {
               
                UIImageView *imageView=(UIImageView *)obj;
               
                NSArray *list2=imageView.subviews;
               
                for (id obj2 in list2) {
                   
                    if ([obj2 isKindOfClass:[UIImageView class]]) {
                       
                        UIImageView *imageView2=(UIImageView *)obj2;
                       
                        imageView2.hidden=YES;
                       
                    }
                   
                }
               
            }
           
        }
       
    }
   
   

}