---
title: "windowDidBecomeMain(_:)"
framework: appkit
role: symbol
role_heading: Instance Method
path: "appkit/nswindowdelegate/windowdidbecomemain(_:)"
---

# windowDidBecomeMain(_:)

Tells the delegate that the window has become main.

## Declaration

```swift
@MainActor optional func windowDidBecomeMain(_ notification: Notification)
```

## Parameters

- `notification`: A notification named doc://com.apple.appkit/documentation/AppKit/NSWindow/didBecomeMainNotification.

## Discussion

Discussion You can retrieve the window object in question by sending object to notification.

## See Also

### Managing Main Status

- [windowDidResignMain(_:)](appkit/nswindowdelegate/windowdidresignmain(_:).md)