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  "title" : "columnDidResizeNotification"
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# columnDidResizeNotification

Posted whenever a column is resized in an `NSOutlineView` object.

```
class let columnDidResizeNotification: NSNotification.Name
```

## Discussion

The notification object is the `NSOutlineView` object in which a column was resized. The `userInfo` dictionary contains the following information:

|Key               |Value                                                                                                             |
|------------------|------------------------------------------------------------------------------------------------------------------|
|`@"NSTableColumn"`|The column that was resized.                                                                                      |
|`@"NSOldWidth"`   |An <doc://com.apple.documentation/documentation/Foundation/NSNumber> object containing the column’s original width|

To observe this notification using Swift concurrency, use [`NSOutlineView.ColumnDidResizeMessage`](/documentation/AppKit/NSOutlineView/ColumnDidResizeMessage).

---

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