我的2美分的漂亮和更简单的代码的batuhankrbb，显示使用定时器中的ispresents…或者其他东西…(我将使用它在url回调..)

//
//  ContentView.swift
//
//  Created by ing.conti on 27/01/21.


import SwiftUI

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



struct ContentView: View {
    @State var isPresented = false
    @State var counter = 0
    var body: some View {
        
        VStack{
            Text("Hello, world! \(counter)")
                .padding()
            
            ActivityIndicatorView(isPresented: $isPresented)
        }.onAppear(perform: {
            _ = startRefreshing()
        })
    }
    
    
    
    func startRefreshing()->Timer{
        
        let timer = Timer.scheduledTimer(withTimeInterval: 1, repeats: true) { timer in
            
            counter+=1
            print(counter)
            if counter>2{
                isPresented = true
            }
            
            if counter>4{
                isPresented = false
                timer.invalidate()
            }
        }
        return timer
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

试试这个:

import SwiftUI

struct LoadingPlaceholder: View {
    var text = "Loading..."
    init(text:String ) {
        self.text = text
    }
    var body: some View {
        VStack(content: {
            ProgressView(self.text)
        })
    }
}

更多关于SwiftUI ProgressView的信息

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)
 }
}

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))
        }
    }
}

SwiftUI中的活动指标

import SwiftUI

struct Indicator: View {

    @State var animateTrimPath = false
    @State var rotaeInfinity = false

    var body: some View {

        ZStack {
            Color.black
                .edgesIgnoringSafeArea(.all)
            ZStack {
                Path { path in
                    path.addLines([
                        .init(x: 2, y: 1),
                        .init(x: 1, y: 0),
                        .init(x: 0, y: 1),
                        .init(x: 1, y: 2),
                        .init(x: 3, y: 0),
                        .init(x: 4, y: 1),
                        .init(x: 3, y: 2),
                        .init(x: 2, y: 1)
                    ])
                }
                .trim(from: animateTrimPath ? 1/0.99 : 0, to: animateTrimPath ? 1/0.99 : 1)
                .scale(50, anchor: .topLeading)
                .stroke(Color.yellow, lineWidth: 20)
                .offset(x: 110, y: 350)
                .animation(Animation.easeInOut(duration: 1.5).repeatForever(autoreverses: true))
                .onAppear() {
                    self.animateTrimPath.toggle()
                }
            }
            .rotationEffect(.degrees(rotaeInfinity ? 0 : -360))
            .scaleEffect(0.3, anchor: .center)
            .animation(Animation.easeInOut(duration: 1.5)
            .repeatForever(autoreverses: false))
            .onAppear(){
                self.rotaeInfinity.toggle()
            }
        }
    }
}

struct Indicator_Previews: PreviewProvider {
    static var previews: some View {
        Indicator()
    }
}

// Activity View

struct ActivityIndicator: UIViewRepresentable {

    let style: UIActivityIndicatorView.Style
    @Binding var animate: Bool

    private let spinner: UIActivityIndicatorView = {
        $0.hidesWhenStopped = true
        return $0
    }(UIActivityIndicatorView(style: .medium))

    func makeUIView(context: UIViewRepresentableContext<ActivityIndicator>) -> UIActivityIndicatorView {
        spinner.style = style
        return spinner
    }

    func updateUIView(_ uiView: UIActivityIndicatorView, context: UIViewRepresentableContext<ActivityIndicator>) {
        animate ? uiView.startAnimating() : uiView.stopAnimating()
    }

    func configure(_ indicator: (UIActivityIndicatorView) -> Void) -> some View {
        indicator(spinner)
        return self
    }   
}

// Usage
struct ContentView: View {

    @State var animate = false

    var body: some View {
            ActivityIndicator(style: .large, animate: $animate)
                .configure {
                    $0.color = .red
            }
            .background(Color.blue)
    }
}