隐藏/改变导航条底部的黑线

最新推荐文章于 2024-04-25 07:57:01 发布

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本文介绍三种有效的方法来解决iOS应用中导航栏底部出现的黑线问题：通过修改viewWillDisappear和viewWillAppear方法调整navigationBar样式；遍历视图层级定位并隐藏黑线；自定义视图覆盖或使用setShadowImage方法更改阴影图像。

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直接上方法:

1.隐藏黑线:(会影响navigationBar的translucent属性)

- (void)viewWillDisappear:(BOOL)animated{

    [self.navigationController.navigationBar setBackgroundImage:nil forBarMetrics:UIBarMetricsDefault];
    [self.navigationController.navigationBar setShadowImage:nil];
}

如果不想影响下个界面的效果:

- (void)viewWillAppear:(BOOL)animated
{
    [self.navigationController.navigationBar setBackgroundImage:[UIImage new] forBarMetrics:UIBarMetricsDefault];
    [self.navigationController.navigationBar setShadowImage:[UIImage new]];
}

2.遍历找出这条黑线,再做相应的处理:

先写个方法,用来找出这条黑线:

 - (UIImageView *)findBottomLineInView:(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 findBottomLineInView:subview];
        if (imageView) {
            return imageView;
        }
    }
    return nil;
}

然后再做相应处理:

- (void)viewWillAppear:(BOOL)animated {
    UIImageView *navBarBottomLine = [self findBottomLineInView:self.navigationController.navigationBar];
    navBarBottomLine.hidden = YES;
}

也可以自定义view直接覆盖:

 UIImageView *navLine = [[UIImageView alloc] initWithFrame:navBarBottomLine.frame];
 navLine.backgroundColor = [UIColor RedColor];
 [self.navigationController.view addSubview:navLine];
 navLine.backgroundColor = [UIColor blueColor];
 [self.navigationController.view addSubview:navLine];

3.利用setShadowImage:方法

给UIImage写个分类---->用颜色值来创建一张图片

+ (UIImage *)imageWithColor:(UIColor *)color withSize:(CGSize)size
{
    CGRect rect = CGRectMake(0.0f, 0.0f, size.width, size.height);
    UIGraphicsBeginImageContext(rect.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    
    CGContextSetFillColorWithColor(context, [color CGColor]);
    CGContextFillRect(context, rect);
    
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    return image;
}

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    
    [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleDefault];
    [self.navigationController.navigationBar setBackgroundImage:[UIImage imageWithColor:[UIColor colorWithRed:248/255.0 green:248/255.0 blue:248/255.0 alpha:1.0] withSize:CGSizeMake(self.view.frame.size.width, 1)] forBarMetrics:UIBarMetricsDefault];
    [self.navigationController.navigationBar setShadowImage:[UIImage imageWithColor:[UIColor colorWithRed:199/255.0 green:199/255.0 blue:199/255.0 alpha:0.5] withSize:CGSizeMake(self.view.frame.size.width, 1)]];
    [self.navigationController.navigationBar setBarTintColor:[UIColor colorWithRed:50/255.0 green:50/255.0 blue:50/255.0 alpha:1.0]];
}

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
    
    [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent];
    [self.navigationController.navigationBar setBackgroundImage:[UIImage imageWithColor:[UIColor colorWithRed:136/255.0 green:240/255.0 blue:0 alpha:1.0] withSize:CGSizeMake(self.view.frame.size.width, 1)] forBarMetrics:UIBarMetricsDefault];
    [self.navigationController.navigationBar setBarTintColor:[UIColor whiteColor]];
}

这样就可以做到分开单独设置或者统一设置