how to handle group subtotal and e.g. target rows in WPF DataGrid?
I'm implementing a WPF DataGrid that contains projects with many key figures. Projects are grouped by project categories. For each category there should be: a row that shows in each key figure column sum of all rows for the column. a target row that is not part of the datasource grid in binded to. target row tells for every column what is target for the year (e.g. how much money there's to spend). These rows should be always on top in each group (sorting filtering). My 1st solution was to have this data in group header. This is not a good solution because group header does not support columns.