相关疑难解决方法(0)

当我在 NavigationView 中放置显式动画时，作为不良副作用，它会为 NavigationView 内容的初始布局设置动画。无限动画会变得特别糟糕。有没有办法禁用这种副作用？

示例：下图应该是全屏蓝色背景上的红色动画加载器。相反，我得到了缩放蓝色背景的无限循环：

import SwiftUI

struct EscapingAnimationTest: View {
    var body: some View {
        NavigationView {
            VStack {
                Spacer()
                EscapingAnimationTest_Inner()
                Spacer()
            }
            .backgroundFill(Color.blue)
        }
    }
}

struct EscapingAnimationTest_Inner: View {
    @State var degrees: CGFloat = 0
    
    var body: some View {
        Circle()
            .trim(from: 0.0, to: 0.3)
            .stroke(Color.red, lineWidth: 5)
            .rotationEffect(Angle(degrees: degrees))
            .onAppear() {
                withAnimation(Animation.linear(duration: 1).repeatForever(autoreverses: false)) {
                    degrees = 360
                }
            }
    }
}

struct EscapingAnimationTest_Previews: PreviewProvider {
    static var previews: some View {
        EscapingAnimationTest()
    }
}

我正在尝试在 SwiftUI 中创建一个简单的动画。它基本上是一个改变其框架的矩形，同时保持在父视图的中心。

struct ContentView: View {
    var body: some View {
        NavigationView {
            VStack {
                Text("Text")
                ZStack {
                    Color.blue
                    SquareAnimation().frame(width: 200, height: 200, alignment: .center)
                }
                Text("Text")
            }
        }
    }
}

struct SquareAnimation: View {
    var currentRect = CGRect(x: 0, y: 0, width: 50, height: 50)
    var finalRect = CGRect(x: 0, y: 0, width: 100, height: 100)
    
    private let animation = Animation.easeInOut(duration: 1).repeatForever(autoreverses: true)
    
    @State var animate = false
    
    var body: some View {
        ZStack() {
            Color.clear
            Rectangle()
                .frame(width: …