Swift-如何动态创建标签

Question

I have created some code which reads through an array and saves data for each index into variables which I then pass onto to a created label.

Below is the code: example of data arr content : ["2,5","5,1"] two indexes inside array

for i in 0..<dataArr.count {
let element = dataArr[i]
let labelNum = UILabel()
label split = element.components(separatedBy: ",")

let num1 = split[0]
let num2 = split[1]

let num1Nnum2 = "number 1 :" + num1 + " number 2:" + num2
labelnum.text = num1Nnum2
labelnum.textAlignment = .center
labelnum.frame = CGRect( x:10, y:90, width:250, height: 80)
self.view.addSubview(labelnum)

}

how can I create it so that when the label is created the second time when it reads index[1] it creates a new label with same code but drop the label under the first label. I have tried to do :

labelnum[i] to attempt to create a new label using the value of index for example labelnum1 when i is = 1.

Any help will be Appreciated.

Answer 1

There is UIStackView in iOS which lets you add elements dynamically at the bottom or top of the existing views. You can always add a new label which automatically appears at the bottom of the view. You can also accomplish this with UITableView or UIScrollView .

Here is an example of UIStackView , dynamically appending new label below previous one. I hope you can infer this for your use case,

class ViewController: UIViewController {

    var lastLabelCount = 0

    var stackView: UIStackView!

    override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = UIColor.white
        let tap = UITapGestureRecognizer(target: self,
                                         action: #selector(tapped))
        view.addGestureRecognizer(tap)
        createViews()
    }

    func createViews() {
        stackView = UIStackView(frame: .zero)
        stackView.translatesAutoresizingMaskIntoConstraints = false
        stackView.axis = .vertical
        stackView.alignment = .top
        view.addSubview(stackView)

        NSLayoutConstraint.activate([
            stackView.leftAnchor.constraint(equalTo: view.leftAnchor),
            stackView.rightAnchor.constraint(equalTo: view.rightAnchor),
            stackView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor),
            ])
    }

    @objc func tapped() {
        let label = UILabel(frame: .zero)
        label.translatesAutoresizingMaskIntoConstraints = false
        label.textColor = UIColor.black
        label.text = "Hi I am label \(lastLabelCount)"
        stackView.addArrangedSubview(label)

        lastLabelCount += 1
    }
}

Answer 2

Create a variable to hold Y Position of The Label. and in each iteration add the height of previous label in Y Position variable to drop new label to below previous one.

class ViewController: UIViewController {

let dataArr = ["2,5","5,1"]
override func viewDidLoad() {
    super.viewDidLoad()
    var yPos = 90
    for i in 0..<dataArr.count {
        let element = dataArr[i]
        let labelNum = UILabel()
        let split = element.components(separatedBy: ",")

        let num1 = split[0]
        let num2 = split[1]

        let num1Nnum2 = "number 1 :" + num1 + " number 2:" + num2
        labelNum.text = num1Nnum2
        labelNum.textAlignment = .center
        labelNum.frame = CGRect( x:10, y:yPos, width:250, height: 80)
        yPos += 80
        self.view.addSubview(labelNum)

    }

}