SwiftUI 2.0 introduced some convenient built-in controls, such as Label and ProgressView. They have a basic form that is quite common but support custom styles. The intention of the official team is quite clear: by using built-in controls, they aim to standardize code and speed up prototype writing. If more detailed control is needed, it can be achieved by extending the style.
Classic Spinning Indicator
Swift
ProgressView()
Linear Progress Bar
Swift
ProgressView("Completion", value: 50, total: 100)
Code Example
Swift
import SwiftUI
struct ProgressTest: View {
@State var timer = Timer.TimerPublisher(interval: 0.03, runLoop: .main, mode: .common).autoconnect()
@State var value: Double = 0.0
var body: some View {
List {
// Unable to define color
ProgressView()
// Unable to hide Label
ProgressView("Completion", value: value, total: 100)
.accentColor(.red)
// Custom Style
ProgressView("Project Progress", value: value, total: 100)
.progressViewStyle(MyProgressViewStyle())
}
.onAppear {
timer = Timer.TimerPublisher(interval: 0.03, runLoop: .main, mode: .common).autoconnect()
}
.onReceive(timer) { _ in
if value < 100 {
value += 2
}
}
}
}
// The method definitions are more or less the same.
struct MyProgressViewStyle: ProgressViewStyle {
let foregroundColor: Color
let backgroundColor: Color
init(foregroundColor: Color = .blue, backgroundColor: Color = .orange) {
self.foregroundColor = foregroundColor
self.backgroundColor = backgroundColor
}
func makeBody(configuration: Configuration) -> some View {
GeometryReader { proxy in
ZStack(alignment: .topLeading) {
backgroundColor
Rectangle()
.fill(foregroundColor)
.frame(width: proxy.size.width * CGFloat(configuration.fractionCompleted ?? 0.0))
}.clipShape(RoundedRectangle(cornerRadius: 10))
.overlay(
configuration.label
.foregroundColor(.white)
)
}
}
}
