关于UINavigationController的一些坑和设置

因为近来在项目中踩了一些坑，所以今天写这篇文章的目的就当归纳总结一下

translucent

iOS7及iOS7之后由于navigationBar.translucent默认为YES,原点在（0，0）点，当设置为NO时,原点坐标在（0，64）点屏幕会多一个导航栏的高度,从图层上看的话，控制器相对高度比屏幕高度会低64px。

automaticallyAdjustsScrollViewInsets

当导航栏存在的情况下想让UIScrollView或其子类占据整个视图

if (@available(iOS 11.0, *)) {
        self.tableView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
    } else {
        self.automaticallyAdjustsScrollViewInsets = NO;
        self.edgesForExtendedLayout = UIExtendedEdgeNone;
    }

contentInsetAdjustmentBehavior

iOS11中automaticallyAdjustsScrollViewInsets方法被废弃，我们需要使用UIScrollView的 contentInsetAdjustmentBehavior 属性来替代它。
contentInsetAdjustmentBehavior枚举值：

typedef NS_ENUM(NSInteger, UIScrollViewContentInsetAdjustmentBehavior) {
    UIScrollViewContentInsetAdjustmentAutomatic, 和scrollableAxes一样,scrollView会自动计算和适应顶部和底部的内边距并且在scrollView 不可滚动时,也会设置内边距.
    UIScrollViewContentInsetAdjustmentScrollableAxes, //自动计算内边距.
    UIScrollViewContentInsetAdjustmentNever, //不计算内边距，
    UIScrollViewContentInsetAdjustmentAlways, //根据safeAreaInsets 计算内边距
} API_AVAILABLE(ios(11.0),tvos(11.0));

self.navigationController.navigationBar.translucent = NO;相当于self.automaticallyAdjustsScrollViewInsets = NO;self.edgesForExtendedLayout = UIRectEdgeNone;相当于UIScrollViewContentInsetAdjustmentNever

导航栏透明

if (@available(iOS 13.0, *)) {
        [self.navigationController.navigationBar.standardAppearance configureWithTransparentBackground];
        self.navigationController.navigationBar.standardAppearance.shadowColor = [UIColor clearColor];
    }else{
        //导航栏透明
        [self.navigationController.navigationBar setBackgroundImage:[UIImage new] forBarMetrics:UIBarMetricsDefault];
        //去掉下划线
        self.navigationController.navigationBar.shadowImage = [UIImage new];
    }

或者

//    设置透明导航栏
    UIView *barImageView = self.navigationController.navigationBar.subviews.firstObject;
    barImageView.alpha = 0.0;

导航栏颜色

- (void)setBackColor:(UIColor *)backColor{
    if (@available(iOS 13.0, *)){
        [self.standardAppearance configureWithOpaqueBackground];
        [self.standardAppearance setBackgroundColor:backColor];
        [self.standardAppearance setBackgroundImage:nil];
    }else{
        [self setBackgroundImage:nil forBarMetrics:UIBarMetricsDefault];
        [self setBarTintColor:backColor];
    }
}

恢复系统默认导航栏

    if (@available(iOS 13.0, *)) {
        [self.navigationController.navigationBar.standardAppearance configureWithDefaultBackground];
        self.navigationController.navigationBar.standardAppearance.shadowImage = nil;
    } else {
        // Fallback on earlier versions
    }

导航栏字体颜色

- (void)setTitleColor:(UIColor *)titleColor font:(UIFont *)font{
    //文字颜色
    if (@available(iOS 13.0, *)){//这个方法和self.navigationController.navigationBar.barTintColor = [UIColor greenColor];这个方法有冲突，这样设置了字体颜色和大小之后，导航栏的颜色设置就没效果了
        [self.navigationController.navigationBar.standardAppearance setTitleTextAttributes:@{NSFontAttributeName:font, NSForegroundColorAttributeName:titleColor}];
    }else{
        [self.navigationController.navigationBar setTitleTextAttributes:@{NSFontAttributeName:font , NSForegroundColorAttributeName:titleColor}];
    }
}

暂时就这些了吧，后面想到了再补充。