xcode – Auto Resizing of NSTableView Content Not Working

Along the same lines as How to Expand NSTableCellView Width When Resizing Column in NSTableView – but the solution there isn’t working for me…

I’ve got a Mac app in Xcode 12.3 with some table views which adjust their width according to the size of the window – but I cannot get the table contents to adjust their width to fill the columns.

Here’s a view debug of what I’m seeing:

View Debug of NSTableView

The NSTableCellView width is 287, but the NSTableRowView is 343.

I’ve got Autoresizes Subviews turned on all the way down the hierarchy, and I’ve got leading and trailing constraints from the Table View Cell to its superview – but I can’t get it working.

Any clues? Many thanks!