Powerpoint issue when quitting

Question

I have some c# code which opens a Powerpoint slide, refreshes the graphs, and then quits.

This works fine, unless the user already has a Powerpoint slide open, in which

Answer 1

You could check how many other Presentations are open, and only quit if yours is the only one:

ppPres.SaveAs(outputFilename);

var presentations = ppApp.Presentations;

if (presentations.Count <= 1)
{
    ppPres.Close(); 
    ppApp.Quit();
}