obtain the scrollView's offset

Before iOS 16, you could get the ScrollView’s offset using the following code. However, if the UI becomes complex, the scrollViewOffset will not update while scrolling.

ScrollView {
	VStack(alignment: .leading, spacing: 32) {
		// 1. 将监测器独立出来，包裹在无间距的 VStack 中以避免布局干扰
		VStack(spacing: 0) {
			Color.clear
				.frame(height: 0) // 占据 0 高度，不可见但存在
				.background(
				    GeometryReader { proxy in
				        Color.clear
				            .preference(
				                key: ScrollOffsetKey.self,
				                value: proxy.frame(in: .named("scroll")).minY
				            )
				    }
				)

			LargeNavBarView()
				.opacity(largeHeaderOpacity)
		}

		ContentArea
	}
	.padding(.horizontal, 24)
}
.coordinateSpace(name: "scroll")
.onPreferenceChange(ScrollOffsetKey.self) { value in 
    self.scrollOffset = value 
}

After iOS 16, you can reliably obtain the scrollView’s offset using the following code.

ScrollView {
	VStack(alignment: .leading, spacing: 32) {
		// 1. 将监测器独立出来，包裹在无间距的 VStack 中以避免布局干扰
		VStack(spacing: 0) {
			Color.clear
				.frame(height: 0) // 占据 0 高度，不可见但存在
				.onGeometryChange(for: CGFloat.self) { proxy in
					proxy.frame(in: .named("scroll")).minY
				} action: { newValue in
					self.scrollOffset = newValue
					print("scrollOffset: \(self.scrollOffset)")
				}

			LargeNavBarView()
				.opacity(largeHeaderOpacity)
		}

		ContentArea
	}
	.padding(.horizontal, 24)
}