我有两个子视图:紫色的属于一个主视图,使用以下语法它可以很好地工作:
sSubview.center = view.center
橙色的属于紫色视图,但同样的语法没有将它正确地放在中心位置。 你能看出我的错误在哪里吗?
Here is my code:
import UIKit
class ViewController: UIViewController {
var sSubview = UIView()
var sLabel = UILabel()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
view.backgroundColor = UIColor.lightGray
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func viewDidLayoutSubviews() {
createSimplestSubview()
}
// First subview
func createSimplestSubview() {
sSubview = UIView(frame: CGRect(x: 0, y: 0, width: view.frame.width * 0.9, height: view.frame.height * 0.9))
sSubview.backgroundColor = UIColor.purple // just for test, to make it visible
sSubview.center = view.center // that s pretty easy!
view.addSubview(sSubview)
createSimplestLabel()
}
// Second subview
func createSimplestLabel() {
sLabel = UILabel(frame: CGRect(x: 0, y: 0, width: sSubview.frame.width * 0.3, height: sSubview.frame.height * 0.2))
sLabel.backgroundColor = UIColor.orange // just for test, to make it visible
sLabel.center = sSubview.center
sLabel.text = "This label has to be centered!"
sLabel.textAlignment = .center
sLabel.numberOfLines = 0
sSubview.addSubview(sLabel)
}
这里有一个屏幕截图:
guard let
代替!
。 - Alistra