If you're looking for a quick and dirty workaround, you can create a shortcut to your executable in '%AppData%MicrosoftWindowsSendTo' Now you can select a bunch of files, right click, select Send To, and your application.
This will pass all the selected files as individual command line options to one instance of your application... keep in mind there is a 32767 character command line limit which will limit the number of files you can pass to your application using this method, and make sure your program wont' try to open files it doesn't know how to deal with. In the long run, Factor Mystic's method is way better.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…