问题描述
这是我的代码，
func bannerNotification(text: String){
let container = UIView()
let image = UIImageView()
let label = UILabel()
container.frame = CGRect(x: 0,y:0,width: self.view.frame.size.width,height: 100)
container.backgroundColor = .blue
image.frame = CGRect(x: 15,y: 50,width: 30,height: 30)
image.image = UIImage(named: "passport")
label.frame = CGRect(x: image.bounds.maxX + 35,width: container.frame.size.width - 100,height: 50)
label.backgroundColor = .red
label.numberOfLines = 0
label.font = UIFont(name:"Helvetica Neue",size: 15)
label.text = text
container.addSubview(image)
container.addSubview(label)
self.view.addSubview(container)
}
根据此代码，容器和图片会显示在正确的位置，但是如果我传递小文本，以使我的文字与图片不对齐，则表示我的图片顶部位置和文本顶部位置应该相同
如果我要传递较大的文本，则容器底部和标签底部应相同，并且所有文本都不应被截断，并且图像和标签应从顶部内嵌 >。
解决方法
您真的想为此使用自动布局，尤其是因为您使用的是多行标签-这意味着高度会有所不同。
这是一个示例-阅读注释以了解自动布局约束：
class KingViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
bannerNotification(text: "Banner Test")
//bannerNotification(text: "Banner Test with lots of text to wrap onto multiple lines. Of the many advantages with using auto-layout,notice that the banner will stretch when you rotate the device.")
}
func bannerNotification(text: String){
let container = UIView()
let image = UIImageView()
let label = UILabel()
container.addSubview(image)
container.addSubview(label)
self.view.addSubview(container)
[image,label,container].forEach {
$0.translatesAutoresizingMaskIntoConstraints = false
}
container.backgroundColor = UIColor(red: 0.0,green: 0.5,blue: 1.0,alpha: 1.0)
//image.image = UIImage(named: "passport")
image.image = UIImage(named: "swiftRed")
label.backgroundColor = .yellow
label.numberOfLines = 0
label.font = UIFont(name:"Helvetica Neue",size: 15)
label.text = text
// respect the safe area
let g = view.safeAreaLayoutGuide
NSLayoutConstraint.activate([
// constrain container Top / Leading / Trailing
container.topAnchor.constraint(equalTo: view.topAnchor),container.leadingAnchor.constraint(equalTo: view.leadingAnchor),container.trailingAnchor.constraint(equalTo: view.trailingAnchor),// we'll use the label height to determine the container height
// image view Top = 8 / Leading = 15
image.topAnchor.constraint(equalTo: g.topAnchor,constant: 8.0),image.leadingAnchor.constraint(equalTo: g.leadingAnchor,constant: 15.0),// image view width = 30 / height == width (1:1 ratio)
image.widthAnchor.constraint(equalToConstant: 30.0),image.heightAnchor.constraint(equalTo: image.widthAnchor),// label Top aligned to Top of image view
label.topAnchor.constraint(equalTo: image.topAnchor),// label Leading == image view Trailing + 20
label.leadingAnchor.constraint(equalTo: image.trailingAnchor,constant: 20.0),// label Trailing = container Trailing - 15
label.trailingAnchor.constraint(equalTo: g.trailingAnchor,constant: -15.0),// container bottom should be
// At Least 8-pts below the image view bottom
// AND
// At Least 8-pts below the label bottom
container.bottomAnchor.constraint(greaterThanOrEqualTo: image.bottomAnchor,container.bottomAnchor.constraint(greaterThanOrEqualTo: label.bottomAnchor,])
}
}
结果，带有短文本：
长文本结果：
请注意，当尺寸更改时（例如随着设备旋转）它会自动调整：
