如何崩溃和淡入Swiftui

Question

启用用于不透明度的单独状态变量并独立进行动画，您可以使不透明度取决于

headerOffset

：

Answer 1

// ScrollToHideView

// @State private var opacity = 1.0

.safeAreaInset(edge: .top, spacing: 0) {
    HeaderView()
        .padding(.bottom, 16)
        .frame(height: headerHeight, alignment: .bottom)
        .background(.blue)
        .opacity(1.0 - min(1.0, max(0.0, headerOffset / headerHeight))) // 👈 here
        .offset(y: -headerOffset)
}

// animating opacity
// withAnimation(.easeIn(duration: 2)) {
//     if self.isScrollingUp {
//         opacity = 0
//     } else {
//         opacity = 1
//     }
// }