How to make Tooltips display on disabled WPF controls

This is old news but I find lots of people still don't know about this.

By default, WPF does not show tooltips on controls that have been disabled. To fix this, set the attached property ToolTipService.ShowOnDisabled.

E.g.

<Button Content="Example Button" 

 ToolTipService.ShowOnDisabled="True"  

 ToolTip="I’m visible even when the control is not enabled"/>