去除navigationBar上那條線:
///隐藏navigationBar導航欄線(直接寫在UINavigationController-viewDidLoad方法裡面即可)
UIView *backgroundView = [self.navigationBar subviews].firstObject;
_lineView = backgroundView.subviews.firstObject;
_lineView.hidden = YES;
///隐藏navigationBar導航欄線(直接寫在UINavigationController-viewDidLoad方法裡面即可)
UIView *backgroundView = [self.navigationBar subviews].firstObject;
_lineView = backgroundView.subviews.firstObject;
_lineView.hidden = YES;