iOS开发一句话隐藏导航栏下的黑线

怼烎@ 2022-06-17 00:08 198阅读 0赞

> > 之前项目要求隐藏导航栏下的黑线，写了很多代码
> 
> 后来在iOS10上不好使了

## 1、之前用的这个方法： ##

--------------------

- (void)viewWillAppear:(BOOL)animated{
        [super viewWillAppear:animated];
    
        [self.navigationController.navigationBar.subviews enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
            if ([obj isKindOfClass:NSClassFromString(@"_UINavigationBarBackground")]){
                UIView * v = obj;
                if (v.subviews.count)
                {
                    navBottomLine = [v.subviews firstObject];
                }
                * stop=YES;
            }
        }];
        navBottomLine.hidden = YES;
    }

## 2、iOS10出来之后，`@"_UINavigationBarBackground"` 变成了`@"_UIBarBackground"`，代码改成这样： ##

--------------------

#define iOS10 ([[UIDevice currentDevice].systemVersion intValue]>=10?YES:NO)
    - (void)viewWillAppear:(BOOL)animated{
        [super viewWillAppear:animated];
    
        [self.navigationController.navigationBar.subviews enumerateObjectsUsingBlock:^(UIView *view, NSUInteger idx, BOOL *stop) {
            if (iOS10) {
                //iOS10,改变了导航栏的私有接口为_UIBarBackground
                if ([view isKindOfClass:NSClassFromString(@"_UIBarBackground")]) {
    
                    [view.subviews firstObject].hidden = YES;
                }
            }else{
                //iOS10之前使用的是_UINavigationBarBackground
                if ([view isKindOfClass:NSClassFromString(@"_UINavigationBarBackground")]) {
    
                    [view.subviews firstObject].hidden = YES;
                }
            }
        }];
    }

## 3、可不可以精简一下呢： ##

--------------------

#### 如果设置了 ####

`[UINavigationBar appearance].translucent = NO;`

**这么写**

- (void)viewWillAppear:(BOOL)animated{
        [super viewWillAppear:animated];
    
        self.navigationController.navigationBar.subviews[0].subviews[0].hidden = YES;
    }

**否则**

- (void)viewWillAppear:(BOOL)animated{
        [super viewWillAppear:animated];
    
        self.navigationController.navigationBar.subviews[0].subviews[1].hidden = YES;
    }

***隐藏黑线之前和之后对比图***

![对比图][1240]

> > > > > 共
> > > > 
> > > > 同
> > > 
> > > 进
> > 
> > 步
> 
> O(∩\_∩)O

[1240]: /images/20220617/2ce4e1e1f4cc463b9a92ef4e7c708009.png