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# init(_:)

Creates a UIKit app delegate adaptor.

```
@MainActor @preconcurrency init(_ delegateType: DelegateType.Type = DelegateType.self)
```

## Parameters

`delegateType`

The type of application delegate that you
define in your app, which conforms to the
<doc://com.apple.documentation/documentation/UIKit/UIApplicationDelegate>
protocol.

## Discussion

Call this initializer indirectly by creating a property with the
`UIApplicationDelegateAdaptor` property wrapper from inside your
`App` declaration:

```
@main
struct MyApp: App {
    @UIApplicationDelegateAdaptor private var appDelegate: MyAppDelegate

    var body: some Scene { ... }
}
```

SwiftUI initializes the delegate and manages its lifetime, calling upon
it to handle application delegate callbacks.

If you want SwiftUI to put the instantiated delegate in the
`Environment`, make sure the delegate class also conforms to the
<doc://com.apple.documentation/documentation/Combine/ObservableObject>
protocol. That causes SwiftUI to invoke the `init(_:)-8vsx1`
initializer rather than this one.

---

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