Hi matlab22,
You didn't specify any
Content
for your groupbox. Use a StackPanel as Content-Container then add your sub-stackpanels
<groupbox grid.columnspan="2">
<groupbox.header>Control</groupbox.header>
<stackpanel>
<stackpanel grid.column="0" orientation="Horizontal" horizontalalignment="Left"></stackpanel></stackpanel></groupbox>
btw. nothing wrong to set the margin - maybe through a style? And you are not counting pixels but "device units" ;-)
If you don't understand what I mean or need further help, feel free to ask..
Kind regards
Johannes