Make sure the code I posted above is in myMusicFullscreenVisualization.xml. MP needs those id's for some really weird (in a doesn't-make-sense-way) reason.
It worked for me, see if it helps.
For the developers: while I was troubleshooting I gave the container (musicFullscreen.xml) a red background and that showed me that the container does scale to fullscreen. It's just the Windows-control that doesn't scale.
It worked for me, see if it helps.
For the developers: while I was troubleshooting I gave the container (musicFullscreen.xml) a red background and that showed me that the container does scale to fullscreen. It's just the Windows-control that doesn't scale.