I've written a Lyric Generator for lower-third church song lyrics, using vMixInterop. The user control is designed to allow for multiple instances to be open in the Input Bar (bottom row), corresponding to Song 1, Song 2, etc. Each set of song lyrics are displayed in separate Windows Forms, and everything works fine.

The problem is: when Song 1 ends, the director minimizes that window, and switches to Song 2 window. However, it's easy to forget to click "Overlay 1" for Song 2 in the Input Bar (bottom row). So anything he does in Song 2 has no effect, because Song 1 is still set to Overlay 1.

I want to add a feature that if a specific Song window gets focus, "Overlay 1" is activated for that XAML input. I'd like to do this with an API, rather than using SendKeys or an HttpWebRequest object, as they are too brittle and rely on specific Shortcuts and Options to be in place.

Thank you,

Jon