Question

I would like to know which process will be fired before a file is started with:

Process.Start("PathToFile");

Then I would like to have the path to the process.

Thank you.

Answer 1

You can look at the MainModule property of the Process returned from Process.Start:

Process p = Process.Start(@"D:\\test.txt");
string executableStarted = p.MainModule.FileName; // full path to notepad.exe

However, you should remember that the return value from Proces.Start might be null – according to MSDN, the return value is:

A new Process component that is
associated with the process resource,
or null, if no process resource is
started (for example, if an existing
process is reused).

Update

In order to know the executable prior to launching the process, you will have to look under HKEY_CLASSES_ROOT in the registry. This would be the code for going from a file name to the command the shell will execute when opening the file:

string extension = Path.GetExtension(path);
var regClasses = Microsoft.Win32.Registry.ClassesRoot;
var extensionKey = regClasses.OpenSubKey(extension);
var typeKey = extensionKey.GetValue(String.Empty); 
var cmdKey = regClasses.OpenSubKey(typeKey + @"\shell\open\command");
string command = cmdKey.GetValue(null) as string;