iOS10 去掉导航栏分割线

if ([self.navigationController.navigationBar respondsToSelector:@selector( setBackgroundImage:forBarMetrics:)])
{

NSArray *list=self.navigationController.navigationBar.subviews;

for (id obj in list)
{

if ([UIDevice currentDevice].systemVersion.floatValue >= 10.0)
{//10.0的系统字段不一样
UIView *view = (UIView*)obj;
for (id obj2 in view.subviews) {

if ([obj2 isKindOfClass:[UIImageView class]])
{

UIImageView *image =  (UIImageView*)obj2;
image.hidden = YES;
}
}
}
}
}