如何判断用户何时滚动到了LazyVGrid的底部？

import SwiftUI

struct ContentView: View {
    @State private var data = [1, 2, 3, 4, 5]
    
    var body: some View {
        ScrollViewReader { scrollViewProxy in
            LazyVGrid(columns: [GridItem(.adaptive(minimum: 100))]) {
                ForEach(data, id: \.self) { item in
                    Text("\(item)")
                        .frame(height: 100)
                        .onAppear {
                            // 判断是否滚动到了底部
                            if item == data.last {
                                let lastIndex = data.count - 1
                                let lastIndexProxy = scrollViewProxy.proxy(for: data[lastIndex])
                                let lastIndexFrame = scrollViewProxy.frame(for: lastIndexProxy)
                                let contentHeight = scrollViewProxy.contentSize.height
                                
                                if lastIndexFrame.maxY <= contentHeight {
                                    // 加载更多数据
                                    loadMoreData()
                                }
                            }
                        }
                }
            }
            .onAppear {
                // 初始加载数据
                loadMoreData()
            }
        }
    }
    
    func loadMoreData() {
        // 模拟加载更多数据
        let newData = data.last! + 1
        data.append(newData)
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}