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# preferredMaximumSize

For a view controller that is part of an app extension, the largest allowable size for the app extension’s primary view, in screen units.

```
var preferredMaximumSize: NSSize { get }
```

## Discussion

An app extension should return the maximum dimensions that are potentially useful for its root view, based on the items the service has been sent.  By default, the value of this property is a large or infinite size.

## See Also

[`preferredContentSize`](/documentation/AppKit/NSViewController/preferredContentSize)

The desired size of the view controller’s view, in screen units.


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