There is a WPF DataGrid with columns that have checkboxes. These checkboxes are already bound to some data source. What we want is a checkbox for each column that checks/unchecks all the checkboxes (and as a result updates the data source so that all the values are the same).
Existing solutions on here work if there isn't an existing datasource - but we have effectively two, the 'select all' checkboxes and the actual data that the other checkboxes in the rows are bound to, if that makes sense.
If we could use a trigger or somesuch instead of 'code behind' that would be ideal. Is there a declarative solution?