I need from my C# application open a PDF file by using Foxit Reader or Adobe Reader in full screen mode. Manually, I do it typing F11 in Foxit Reader and CTRL+L on Adobe Reader. This changes the current file view to "full screen" mode. But programmatically, I have no idea how to do this! Thanks in advance.
as I'm opening the pdf file:
Process.Start(filename);
You can use SendKeys to send F11 or CTRL+L to the PDF application after you run it.
Alternatively, Foxit or Adobe may support commandline parameters to open in fullscreen mode. If you don't mind changing to SumatraPDF, I do know you can pass -presentation $file.pdf - opens a PDF file in presentation (full-screen) mode. See the manual for details.