SwiftUI 更改和动画前景色

Question

I'm new to swiftUI and I am trying to I have a blue view flash green for half a second and then go back to blue. I've tried multiple ways. I have tried setting the color to a state variable but that does not work. In the current code below the view just remains blue. Current implementation

Answer 1

You can do it with State Variable

@State private var color = Color.red
  var body: some View {

      Circle()
        .aspectRatio(contentMode: .fit)
        .foregroundColor(color)
      .onAppear {
        withAnimation(.easeInOut(duration: 4)) {
           self.color = Color.blue

        }
        DispatchQueue.main.asyncAfter(deadline: .now() + 4.0) {
            withAnimation(.easeInOut(duration: 4)){self.color = Color.red }
        }


    }
  }

Answer 2

I wrote this out but it seems to be skipping over the first animation.

@State private var color = Color.blue

var body: some View {
    Circle()
    .aspectRatio(contentMode: .fit)
    .foregroundColor(color)
        .onAppear {
            withAnimation(.easeInOut(duration: 2)) {
                self.color = Color.green
            }
            withAnimation(
                Animation.easeInOut(duration: 2)
                    .delay(2)
                ) {
                self.color = Color.blue
            }
    }
}