[英]how to use EnvironmentObject in a Swiftui View function?
[英]How to use my @EnvironmentObject in AppDelegate in Swiftui (iOS 15 / Xcode 13.2.1)?
我有一个 class:
class AppInfos_M: ObservableObject {
@Published var currentUser: User_M = User_M()
@Published var userTo: User_M = User_M()
}
我将它从 main 声明为 environmentObject:
...
@main
struct TestApp: App {
@UIApplicationDelegateAdaptor(AppDelegate.self) var appDelegate
...
@StateObject var appInfos_M = AppInfos_M()
var body: some Scene {
WindowGroup {
LaunchScreen_V()
.environmentObject(appInfos_M)
...
}
}
}
class 在我的应用程序中运行良好。 现在我需要从 AppDelegate 修改它,因为我需要在收到通知时获取 appInfos_M.userTo.id。 我尝试了几件事,但没有一个有效。 我怎样才能访问它?
在我需要它的所有观点中,我都以这种方式声明并且它工作正常,但在 AppDelegate 中却不行,为什么? :
@EnvironmentObject var appInfos_M: AppInfos_M
这是我尝试过的一项无效的测试:
请注意,3 个小点 (...) 用于放置无用代码。
...
class AppDelegate: NSObject, UIApplicationDelegate {...}
...
@available(iOS 10, *)
extension AppDelegate : UNUserNotificationCenterDelegate {
...
func userNotificationCenter(_ center: UNUserNotificationCenter,
didReceive response: UNNotificationResponse,
withCompletionHandler completionHandler: @escaping () -> Void) {
@EnvironmentObject var appInfos_M: AppInfos_M
let userInfo = response.notification.request.content.userInfo
appInfos_M.userTo.id = "just for testing here" // <- i get this error : Thread 1: Fatal error: No ObservableObject of type AppInfos_M found. A View.environmentObject(_:) for AppInfos_M may be missing as an ancestor of this view.
...
您始终可以像这样将AppInfos_M
存储在您的AppDelegate
中
class AppDelegate: NSObject, UIApplicationDelegate {
var appInfos = AppInfos_M()
(...)
}
然后,您可以将其用作 EnvironmentObject:
...
@main
struct TestApp: App {
@UIApplicationDelegateAdaptor(AppDelegate.self) var appDelegate
...
var body: some Scene {
WindowGroup {
LaunchScreen_V()
.environmentObject(appDelegate.appInfos)
...
}
}
}
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