iOS导航栏底部线条隐藏和显示

奇怪的产品,脑洞大开的UI让人欲罢不能.这个页面要下划线,那个页面又不要,弄得我们很尴尬.

前提

项目中要有BaseViewController和BaseNavigationController

---

BaseNavigationController

Q:为什么要用UIImageView自定义?

A:产品和UI说变就变,为自己以后留一线,谁知道是改颜色还是图片

//寻找底部横线
- (UIImageView *)foundNavigationBarBottomLine:(UIView *)view {
    if ([view isKindOfClass:UIImageView.class] && view.bounds.size.height <= 1.0) {
        return (UIImageView *)view;
    }
    for (UIView *subview in view.subviews) {
        UIImageView *imageView = [self foundNavigationBarBottomLine:subview];
        if (imageView) {
            return imageView;
        }
    }
    return nil;
}

//显示底部横线
- (void)showNavBarBottomLine {
    UIImageView *bottomLine = [self foundNavigationBarBottomLine:self.navigationBar];
    if (bottomLine) {
        bottomLine.hidden = YES;
    }
   
    UIImageView *navLine = [self.navigationBar.subviews[0] viewWithTag:5757];
    if (navLine) {
        navLine.hidden = NO;
        CGRect bottomLineFrame = bottomLine.frame;
        bottomLineFrame.origin.y = CGRectGetMaxY(self.navigationBar.frame);
        navLine.frame = bottomLineFrame;
    }else {
        CGRect bottomLineFrame = bottomLine.frame;
        bottomLineFrame.origin.y = CGRectGetMaxY(self.navigationBar.frame);
        UIImageView *navLine = [[UIImageView alloc] initWithFrame:bottomLineFrame];
        navLine.tag = 5757;
        navLine.backgroundColor = ColorNavSepGapLine;
        if (self.navigationBar.subviews.count) {
            [self.navigationBar.subviews[0] addSubview:navLine];
        }else{
            bottomLine.hidden = NO;
        }
    }
}

//隐藏底部横线
- (void)hideNavBarBottomLine {
    UIImageView *bottomLine = [self foundNavigationBarBottomLine:self.navigationBar];
    if (bottomLine) {
        bottomLine.hidden = YES;
    }
    UIImageView *navLine = [self.navigationBar.subviews[0] viewWithTag:5757];
    if (navLine) {
        navLine.hidden = YES;
    }
}

---

BaseViewController

- (void)showNavBarBottomLine {
    if ([self.navigationController isKindOfClass:[BaseNavigationController class]]) {
        [(BaseNavigationController *)self.navigationController showNavBarBottomLine];
    }
}

- (void)hideNavBarBottomLine {
    if ([self.navigationController isKindOfClass:[BaseNavigationController class]]) {
        [(BaseNavigationController *)self.navigationController hideNavBarBottomLine];
    }
}

---

使用

最后在每一个控制器的willappear和willdisappear去调用就好了.