When using GroupColumns in XamGrid if the Visbility of Columns within a GroupColumn become Colapsed the GroupColumn will also become colasped. This is the behaviour expected however once the GroupColumn has become colapsed even when the Columns within that GroupColumn become Visible again the GroupColumn will never become Visible again.
Here is an example:
Xaml:
Hello,
Thank you for posting!
I have logged this behavior in our tracking system, with an issue ID of 140936. I have linked the development issue to your case CAS-115164-M1M8K6 so that you are automatically updated regarding any updates on it when our development team review it.
Hello Eno,
Our development team had reviewed this issue and stated that this is the design behavior of the control. When the Visibility property of the last visible child of a GroupColumn is set to Collapsed, actually the visibility of the GroupColumn is changed to collapsed. The visibility of the child column stays visible. This is the reason that does not allow the columns to be displayed after checking the checkboxes again. What I could suggest you is including some custom logic to check whether the visibility property of the group column is set to collapsed when it should be visible (A or B checkboxes are checked).
More information regarding the group columns and their visibility could be found in our online documentation: http://help.infragistics.com/Help/NetAdvantage/Silverlight/2013.1/CLR4.0/html/xamGrid_Group_Column.html