除了Mojatba Hosseini的回答，

我做了一些更新，这样就可以把它放在一个快速包中:

活动指标:

import Foundation
import SwiftUI
import UIKit

public struct ActivityIndicator: UIViewRepresentable {

  public typealias UIView = UIActivityIndicatorView
  public var isAnimating: Bool = true
  public var configuration = { (indicator: UIView) in }

 public init(isAnimating: Bool, configuration: ((UIView) -> Void)? = nil) {
    self.isAnimating = isAnimating
    if let configuration = configuration {
        self.configuration = configuration
    }
 }

 public func makeUIView(context: UIViewRepresentableContext<Self>) -> UIView {
    UIView()
 }

 public func updateUIView(_ uiView: UIView, context: 
    UIViewRepresentableContext<Self>) {
     isAnimating ? uiView.startAnimating() : uiView.stopAnimating()
     configuration(uiView)
}}

扩展:

public extension View where Self == ActivityIndicator {
func configure(_ configuration: @escaping (Self.UIView) -> Void) -> Self {
    Self.init(isAnimating: self.isAnimating, configuration: configuration)
 }
}

基本活动指标结果:

在SwiftUI 2.0中，我用ProgressView制作了这个简单易用的自定义视图

这是它的样子:

代码:

import SwiftUI

struct ActivityIndicatorView: View {
    @Binding var isPresented:Bool
    var body: some View {
        if isPresented{
            ZStack{
                RoundedRectangle(cornerRadius: 15).fill(CustomColor.gray.opacity(0.1))
                ProgressView {
                    Text("Loading...")
                        .font(.title2)
                }
            }.frame(width: 120, height: 120, alignment: .center)
            .background(RoundedRectangle(cornerRadius: 25).stroke(CustomColor.gray,lineWidth: 2))
        }
    }
}

在SwiftUI中，我发现一个方便的方法是两步方法:

Create a ViewModifier that will embed your view into ZStack and add progress indicator on top. Could be something like this: struct LoadingIndicator: ViewModifier { let width = UIScreen.main.bounds.width * 0.3 let height = UIScreen.main.bounds.width * 0.3 func body(content: Content) -> some View { return ZStack { content .disabled(true) .blur(radius: 2) //gray background VStack{} .frame(width: UIScreen.main.bounds.width, height: UIScreen.main.bounds.height) .background(Color.gray.opacity(0.2)) .cornerRadius(20) .edgesIgnoringSafeArea(.all) //progress indicator ProgressView() .frame(width: width, height: height) .background(Color.white) .cornerRadius(20) .opacity(1) .shadow(color: Color.gray.opacity(0.5), radius: 4.0, x: 1.0, y: 2.0) } } Create view extension that will make conditional modifier application available to any view: extension View { /// Applies the given transform if the given condition evaluates to `true`. /// - Parameters: /// - condition: The condition to evaluate. /// - transform: The transform to apply to the source `View`. /// - Returns: Either the original `View` or the modified `View` if the condition is `true`. @ViewBuilder func `if`<Content: View>(_ condition: Bool, transform: (Self) -> Content) -> some View { if condition { transform(self) } else { self } } } Usage is very intuitive. Suppose that myView() returns whatever your view is. You just conditionally apply the modifier using .if view extension from step 2: var body: some View { myView() .if(myViewModel.isLoading){ view in view.modifier(LoadingIndicator()) } }

如果是myViewModel。isLoading为false，没有修饰符将被应用，因此加载指示器将不显示。

当然，您可以使用任何类型的进度指示器—默认的或您自己的自定义的。

我使用SwiftUI实现了经典的UIKit指示器。 点击这里查看活动指示器的运行情况

struct ActivityIndicator: View {
  @State private var currentIndex: Int = 0

  func incrementIndex() {
    currentIndex += 1
    DispatchQueue.main.asyncAfter(deadline: .now() + .milliseconds(50), execute: {
      self.incrementIndex()
    })
  }

  var body: some View {
    GeometryReader { (geometry: GeometryProxy) in
      ForEach(0..<12) { index in
        Group {
          Rectangle()
            .cornerRadius(geometry.size.width / 5)
            .frame(width: geometry.size.width / 8, height: geometry.size.height / 3)
            .offset(y: geometry.size.width / 2.25)
            .rotationEffect(.degrees(Double(-360 * index / 12)))
            .opacity(self.setOpacity(for: index))
        }.frame(width: geometry.size.width, height: geometry.size.height)
      }
    }
    .aspectRatio(1, contentMode: .fit)
    .onAppear {
      self.incrementIndex()
    }
  }

  func setOpacity(for index: Int) -> Double {
    let opacityOffset = Double((index + currentIndex - 1) % 11 ) / 12 * 0.9
    return 0.1 + opacityOffset
  }
}

struct ActivityIndicator_Previews: PreviewProvider {
  static var previews: some View {
    ActivityIndicator()
      .frame(width: 50, height: 50)
      .foregroundColor(.blue)
  }
}

除了Mojatba Hosseini的回答，

我做了一些更新，这样就可以把它放在一个快速包中:

活动指标:

import Foundation
import SwiftUI
import UIKit

public struct ActivityIndicator: UIViewRepresentable {

  public typealias UIView = UIActivityIndicatorView
  public var isAnimating: Bool = true
  public var configuration = { (indicator: UIView) in }

 public init(isAnimating: Bool, configuration: ((UIView) -> Void)? = nil) {
    self.isAnimating = isAnimating
    if let configuration = configuration {
        self.configuration = configuration
    }
 }

 public func makeUIView(context: UIViewRepresentableContext<Self>) -> UIView {
    UIView()
 }

 public func updateUIView(_ uiView: UIView, context: 
    UIViewRepresentableContext<Self>) {
     isAnimating ? uiView.startAnimating() : uiView.stopAnimating()
     configuration(uiView)
}}

扩展:

public extension View where Self == ActivityIndicator {
func configure(_ configuration: @escaping (Self.UIView) -> Void) -> Self {
    Self.init(isAnimating: self.isAnimating, configuration: configuration)
 }
}