如何在Swift中心UILabel？

Question

我正试图将一些文字放在中心，但我似乎没有工作。

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.


        let title = UILabel()
        title.text = "Some Sentence"
        title.numberOfLines = 0
        title.frame = CGRectMake(self.view.bounds.size.width/2,50,self.view.bounds.size.width, self.view.bounds.size.height) // x , y, width , height
        title.textAlignment = .Center
        title.sizeToFit()
        title.backgroundColor = UIColor.redColor()
        self.view.addSubview(title)

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

}

这是我正在使用的代码，但这就是我得到的：

它不是屏幕的中心。有人能告诉我我做错了什么吗？

Answer 1

要使UILabel居中，只需添加此行

即可

x和y：

title.center = self.view.center

<强> X

title.center.x = self.view.center.x

<强> Y：

title.center.y = self.view.center.y

Answer 2

自动版式

  

要使您的应用具有未来的发展前景，请使用自动布局锚点而不是设置框架。

1。禁用translatesAutoresizing

implementation 'com.google.firebase:firebase-auth:16.0.1'

2。添加CenterX和CenterY约束

titleLabel.translatesAutoresizingMaskIntoConstraints = false

3。将UILabel的文本对齐方式设置为居中

titleLabel.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true

titleLabel.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true

Answer 3

实际上你正在做的是输入UILabel里面的文字。你想要做的是集中标签。要做到这一点，你可以这样做：

title.frame.origin = CGPoint(x: x, y: y)

如果你想让水平居中，你可以这样做：

title.frame.origin = CGPoint(x: self.view.frame.width / 2, y: yValue)

此外，如果您想将标签的x和y值居中，您可以这样做：

title.frame.origin = CGPoint(x: self.view.frame.width / 2, y: self.view.frame.height / 2)

Answer 4

SWIFT 4

这对我有用，并且似乎更能证明未来。这也适用于多行标签。

override func loadView() {
    self.view = UIView()

    let message = UILabel()
    message.text = "This is a test message that should be centered."
    message.translatesAutoresizingMaskIntoConstraints = false
    message.lineBreakMode = .byWordWrapping
    message.numberOfLines = 0
    message.textAlignment = .center

    self.view.addSubview(message)

    message.widthAnchor.constraint(equalTo: view.widthAnchor).isActive = true
    message.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
    message.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
}

Answer 5

快速3/4/5的代码

在行下方粘贴，覆盖重写func viewDidLoad（）

var noDataLbl: UILabel?

在super.viewDidLoad（）之后粘贴以下代码

noDataLbl = UILabel(frame: CGRect(x: 0, y: self.view.center.y, width: 290, height: 70))
noDataLbl?.textAlignment = .center
noDataLbl?.font = UIFont(name: "Halvetica", size: 18.0)
noDataLbl?.numberOfLines = 0
noDataLbl?.text = "Replace this with your text."
noDataLbl?.lineBreakMode = .byTruncatingTail
view.addSubview(noDataLbl!)
noDataLbl?.isHidden = false
noDataLbl?.center = self.view.center