缩小导航栏中的图像
缩小导航栏中的图像
提问于 2015-05-21 08:47:34
我在导航栏中有一个图像，它有点太大了，并且重叠在导航栏之外。我想缩小图像以适应栏的大小。我现在拥有的代码是：
let banner = UIImage(named: "banner.png")
let imageView = UIImageView(image:banner)
imageView.contentMode = UIViewContentMode.ScaleAspectFit
self.navigationItem.titleView = imageView但ScaleAspectFit似乎不起作用。
编辑:我更新了我的问题，添加了一个框架：
let banner = UIImage(named: "banner.png")
let imageView = UIImageView(image:banner)
var bannerWidth = navigationItem.titleView!.frame.width
var bannerHeight = navigationItem.titleView!.frame.height
var bannerx = navigationItem.titleView!.frame.size.width / 2 - banner!.size.width / 2
var bannery = navigationItem.titleView!.frame.size.height / 2 - banner!.size.height / 2
imageView.frame = CGRect(x: bannerx, y: bannery, width: bannerWidth, height: bannerHeight)
imageView.contentMode = UIViewContentMode.Center
self.navigationItem.titleView = imageView但是我现在得到了这个错误
fatal error: unexpectedly found nil while unwrapping an Optional value在bannerWidth变量声明上。
回答 2
Stack Overflow用户
发布于 2015-05-21 09:54:05
想明白了！使用了错误的导航代码
let banner = UIImage(named: "banner.png")
let imageView = UIImageView(image:banner)
var bannerWidth = navigationController?.navigationBar.frame.size.width
var bannerHeight = navigationController?.navigationBar.frame.size.height
var bannerx = bannerWidth! / 2 - banner!.size.width / 2
var bannery = bannerHeight! / 2 - banner!.size.height / 2
imageView.frame = CGRect(x: bannerx, y: bannery, width: bannerWidth!, height: bannerHeight!)
imageView.contentMode = UIViewContentMode.ScaleAspectFit
self.navigationItem.titleView = imageViewStack Overflow用户
发布于 2019-06-12 03:44:21
要调整图像的大小，请尝试修改navigationItem.titleView的约束，它对我有效。
let banner = UIImage(named: "banner")
let bannerView = UIImageView(image: banner)
bannerView.contentMode = UIViewContentMode.ScaleAspectFit
self.navigationItem.titleView = bannerView
NSLayoutConstraint.activate([self.navigationItem.titleView!.heightAnchor.constraint(equalToConstant: 22),self.navigationItem.titleView!.widthAnchor.constraint(equalToConstant: 128)])页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/30362741
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