为什么我在用户登录时看不到我的动画？

Question

我创建了一个自定义的 LaunchSreen，它在用户未登录时运行良好，但如果他已登录，我们就看不到动画（视图直接转到主页视图，不等待动画显示完成）。

你知道为什么吗？

import SwiftUI

struct LaunchScreen: View {
    @EnvironmentObject var session: SessionStore
    @State private var animationDone = false
    @State private var rotation = 0.0
    
    func getUser () {
        session.listen()
    }
    
    var body: some View {
        Group{
            if (session.session != nil && animationDone) {
                Home()
            }
            else if (session.session == nil && animationDone) {
                Login()
            }
            else {
                ZStack {
                    Color(#colorLiteral(red: 0.259467423, green: 0.5342320204, blue: 0.7349982858, alpha: 1))
                    VStack {
                        HStack (alignment: .center, spacing: 0, content: {
                            
                            Text("Se")
                                .foregroundColor(.white)
                                .font(.system(size: 40))
                            Text("e")
                                .foregroundColor(.white)
                                .font(.system(size: 40))
                                .rotation3DEffect(Angle(degrees: rotation), axis: (x: 0, y: 1, z: 0))
                        })
                    }
                }.edgesIgnoringSafeArea(.all)
            }
        }
        .onAppear{
            withAnimation(Animation.easeInOut(duration: 1)){
                rotation += 180
            }
            withAnimation(Animation.linear.delay(1.5)){
                animationDone = true
            }
        }
        .onAppear(perform: getUser)
    }
}

Answer 1

在这种情况下，解决方案是使用 DispatchQueue 延迟，例如

    }
    .animation(.linear, value: animationDone)             // << this !!
    .onAppear{
        withAnimation(Animation.easeInOut(duration: 1)){
            rotation += 180
        }
        DispatchQueue.main.asyncAfter(deadline: .now() + 1.5) {
            animationDone = true                         // << and this !!
        }
    }

为什么我在用户登录时看不到我的动画？

Why i don't see my animation when user is logged in?

swiftui

uiviewanimation

onappear