Why UILabelViewRepresentable does not respect to given frame? - swift

Question

I have a simple UILabelViewRepresentable and I gave a frame to it! But after using in SwiftUI it became max size! How could I solve the issue from UIKit code part?
struct ContentView: View {
var body: some View {
UILabelViewRepresentable(configuration: { label in
label.text = "Hello, World!"
label.textAlignment = .center
label.backgroundColor = .blue
label.frame = CGRect(x: 0, y: 0, width: 200, height: 50)
})
}
}
struct UILabelViewRepresentable: UIViewRepresentable {
let configuration: (UILabel) -> ()
func makeUIView(context: Context) -> UILabel {
return UILabel()
}
func updateUIView(_ uiView: UILabel, context: Context) {
configuration(uiView)
}
}

Answer 1

The main issue is that this representable will try constrain the UILabel to fill the whole screen. You can avoid this by making a UIView, and making the UILabel a child of that so you can center it in the parent.
Code:
struct UILabelViewRepresentable: UIViewRepresentable {
let configuration: (UILabel) -> ()
func makeUIView(context: Context) -> UIView {
let view = UIView()
view.addSubview(UILabel())
return view
}
func updateUIView(_ uiView: UIView, context: Context) {
let label = uiView.subviews.first! as! UILabel
label.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([
label.centerXAnchor.constraint(equalTo: uiView.centerXAnchor),
label.centerYAnchor.constraint(equalTo: uiView.centerYAnchor)
])
configuration(label)
}
}
Usage:
struct ContentView: View {
var body: some View {
UILabelViewRepresentable(configuration: { label in
label.text = "Hello, World!"
label.textAlignment = .center
label.backgroundColor = .blue
label.sizeToFit()
})
}
}
Result:
Depending on your usage, the label.sizeToFit() can be moved inside the UILabelViewRepresentable.

Answer 2

struct ContentView: View {
var body: some View {
UILabelViewRepresentable(text: "Hello, World!",
center: .center,
frame: CGRect(x: 0,
y: 0,
width: 200,
height: 50),
background: .blue)
}
}
struct UILabelViewRepresentable: UIViewRepresentable {
let text : String
let center: NSTextAlignment
let frame: CGRect
let background: UIColor
func makeUIView(context: Context) -> UIView {
let view = UIView()
let label = UILabel()
label.text = text
label.textAlignment = center
label.backgroundColor = background
label.frame = frame
view.addSubview(label)
return view
}
func updateUIView(_ uiView: UIView, context: Context) {
}
}