尝试在SwiftUI中添加一个全屏活动指示器。

我可以在视图协议中使用.overlay(overlay:)函数。

有了这个,我可以做任何视图叠加,但我找不到iOS默认风格UIActivityIndicatorView等效的SwiftUI。

如何使用SwiftUI创建默认样式微调器?

注意:这不是关于在UIKit框架中添加活动指示器。


当前回答

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()
    }
}

其他回答

// 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)
    }
}
struct ContentView: View {
    
    @State private var isCircleRotating = true
    @State private var animateStart = false
    @State private var animateEnd = true
    
    var body: some View {
        
        ZStack {
            Circle()
                .stroke(lineWidth: 10)
                .fill(Color.init(red: 0.96, green: 0.96, blue: 0.96))
                .frame(width: 150, height: 150)
            
            Circle()
                .trim(from: animateStart ? 1/3 : 1/9, to: animateEnd ? 2/5 : 1)
                .stroke(lineWidth: 10)
                .rotationEffect(.degrees(isCircleRotating ? 360 : 0))
                .frame(width: 150, height: 150)
                .foregroundColor(Color.blue)
                .onAppear() {
                    withAnimation(Animation
                                    .linear(duration: 1)
                                    .repeatForever(autoreverses: false)) {
                        self.isCircleRotating.toggle()
                    }
                    withAnimation(Animation
                                    .linear(duration: 1)
                                    .delay(0.5)
                                    .repeatForever(autoreverses: true)) {
                        self.animateStart.toggle()
                    }
                    withAnimation(Animation
                                    .linear(duration: 1)
                                    .delay(1)
                                    .repeatForever(autoreverses: true)) {
                        self.animateEnd.toggle()
                    }
                }
        }
    }
}

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)
 }
}

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()
    }
}

如果你想要一个swift-ui风格的解决方案,那么神奇的是:

import Foundation
import SwiftUI

struct ActivityIndicator: View {
    
    @State private var isAnimating: Bool = false
    
    var body: some View {
        GeometryReader { (geometry: GeometryProxy) in
            ForEach(0..<5) { index in
                Group {
                    Circle()
                        .frame(width: geometry.size.width / 5, height: geometry.size.height / 5)
                        .scaleEffect(calcScale(index: index))
                        .offset(y: calcYOffset(geometry))
                }.frame(width: geometry.size.width, height: geometry.size.height)
                    .rotationEffect(!self.isAnimating ? .degrees(0) : .degrees(360))
                    .animation(Animation
                                .timingCurve(0.5, 0.15 + Double(index) / 5, 0.25, 1, duration: 1.5)
                                .repeatForever(autoreverses: false))
            }
        }
        .aspectRatio(1, contentMode: .fit)
        .onAppear {
            self.isAnimating = true
        }
    }
    
    func calcScale(index: Int) -> CGFloat {
        return (!isAnimating ? 1 - CGFloat(Float(index)) / 5 : 0.2 + CGFloat(index) / 5)
    }
    
    func calcYOffset(_ geometry: GeometryProxy) -> CGFloat {
        return geometry.size.width / 10 - geometry.size.height / 2
    }
    
}

简单地使用:

ActivityIndicator()
.frame(width: 50, height: 50)

希望能有所帮助!

使用示例:

ActivityIndicator()
    .frame(width: 200, height: 200)
    .foregroundColor(.orange)