swiftui - SwiftUI - 检测视图的全局位置何时发生变化

Question

我实际上是 SwiftUI 的初学者。我想知道是否有办法检测视图的全局位置何时发生变化。目前我可以使用 GeometryReader 获得视图的全局位置，但我绝对无法检测到它何时发生变化。

预先感谢您的帮助 ！

struct VideoView: View {

@State var player : AVPlayer // It is a video player
@State var isplaying = false
@State var showcontrols = false // Don't show controls
@State var value : Float = 0


var body: some View {
    
    GeometryReader { geo in
            VStack{
                
                ZStack{
                    VideoPlayer(player: $player)
                    
                }
                .frame(height: UIScreen.main.bounds.height)
            }
            .background(Color.black.edgesIgnoringSafeArea(.all))
            #IF GLOBAL POSITION OF THIS VIEW IS CHANGING
                if(geo.frame(in: .global).midY < 400){
                    self.player.play()
                    self.isplaying = true
                }
            }
            #ENDIF
        
        
    }
}

}