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  "title" : "cacheImage(in:)"
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# cacheImage(in:)

Stores the window’s raster image from a given rectangle expressed in the window’s base coordinate system.

```
func cacheImage(in rect: NSRect)
```

## Parameters

`rect`

The rectangle representing the image to cache.

## Discussion

This method allows the window to perform temporary drawing, such as a band around the selection as the user drags the mouse, and to quickly restore the previous image by invoking [`restoreCachedImage()`](/documentation/AppKit/NSWindow/restoreCachedImage()) and [`flushIfNeeded()`](/documentation/AppKit/NSWindow/flushIfNeeded()). The next time the window displays, it discards its cached image rectangles. You can also explicitly use [`discardCachedImage()`](/documentation/AppKit/NSWindow/discardCachedImage()) to free the memory occupied by cached image rectangles. `rect` is made integral before caching the image to avoid antialiasing artifacts.

Only the last cached rectangle is remembered and can be restored.

## See Also

[`display()`](/documentation/AppKit/NSWindow/display())

Passes a display message down the window’s view hierarchy, thus redrawing all views within the window.


---

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