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# preservesContentDuringLiveResize

A Boolean value indicating whether the view optimizes live-resize operations by preserving content that has not moved.

```
var preservesContentDuringLiveResize: Bool { get }
```

## Discussion

The default value of this property is <doc://com.apple.documentation/documentation/Swift/false>. If your view supports content preservation, override this property and return <doc://com.apple.documentation/documentation/Swift/true>. Content preservation lets your view decide what to redraw during a live resize operation. If your view supports this feature, you should also provide a custom implementation of the [`setFrameSize(_:)`](/documentation/AppKit/NSView/setFrameSize(_:)) method that invalidates the portions of your view that actually need to be redrawn.

For information on how to implement this feature in your views, see [Cocoa Performance Guidelines](https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/CocoaPerformance/CocoaPerformance.html#//apple_ref/doc/uid/TP40001448).

## See Also

[`setFrameSize(_:)`](/documentation/AppKit/NSView/setFrameSize(_:))

Sets the size of the view’s frame rectangle to the specified dimensions, resizing it within its superview without affecting its coordinate system.


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