Taking multiple files (arguments) from the context menu of a Windows shell in C #

Question

I am writing a C # application and it takes files as an argument, I added it to the shell context menu with the code shown below;

if (((CheckBox)sender).CheckState == CheckState.Checked) { RegistryKey key = Registry.CurrentUser.OpenSubKey("Software\\Classes\\*\\shell\\" + KEY_NAME + "\\command"); if (key == null) { key = Registry.CurrentUser.CreateSubKey("Software\\Classes\\*\\shell\\" + KEY_NAME + "\\command"); key.SetValue("", Application.ExecutablePath + " \"%1\""); } } else if (((CheckBox)sender).CheckState == CheckState.Unchecked) { RegistryKey key = Registry.CurrentUser.OpenSubKey("Software\\Classes\\*\\shell\\" + KEY_NAME); if (key != null) { Registry.CurrentUser.DeleteSubKeyTree("Software\\Classes\\*\\shell\\" + KEY_NAME); } 

It works well, but if I select multiple files, multiple instances of the application are launched. For example, if I select 5 files, open 5 applications, how can I fix this?

Answer 1

Detecting if an instance of your application is already running at startup.

If so, send command line arguments to the running instance and exit the new instance.