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[英]How to send a last message and close the socket when a SwiftUI view is dismissed?
[英]How to clean up environment object after Swiftui view is dismissed?
我有一个相当大的项目,我从故事板和 xib 开始。 现在我正在使用 swiftui 实现一些新视图。 这是我用来执行此操作的代码:
func goToSchedule() {
let scheduleController = ScheduleController()
let vc = UIHostingController(rootView: ScheduleView().environmentObject(scheduleController))
if let topController = UIApplication.topViewController() {
topController.present(vc, animated: true, completion: nil)
}
}
但是当我关闭(向下滑动)视图并再次打开它时出现问题,每次我这样做时都会创建一个环境对象的额外副本,这个对象是一个处理tcp连接的类,缩短的代码如下:
class ScheduleController: ObservableObject, NetworkDelegate {
var didChange = PassthroughSubject<Void, Never>()
@Published var timers = [ScheduleTimer]()
let connection = tcpNetwork()
init() {
connection.delegate = self
}
func send(data: String) {
self.connection.sendMsg(data)
}
func processData(data: String) {
// long function where the received data is parsed and the timers array is updated
}}
观点是这样的:
struct ScheduleView: View {
@EnvironmentObject var scheduleController: ScheduleController
var body: some View {
NavigationView {
List {
ForEach(scheduleController.timers, id: \.self) { timer in
TimerRow(id: timer.id, name: timer.name, startTimer: timer.start, endTimer: timer.end, isActive: timer.isActive)
}
}}
刚刚通过将 EnvironmentObject 替换为 ObservedObject 并将其添加到 ScheduleController 的 deinit 方法中解决了这个问题
deinit() {
connection.cancel()
}
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