title: InstallShield - how to write custom action functions
body: <p>I am trying to create installer using InstallShield and have requirement to execute some code during the installation process. Earlier I was using VS 2015 setup extension to create MSI but due to some advance needs in MSI we are planning to migrated to InstallShield and code that we were executing in <strong>onBeforeInstall / onAfterInstall of ServiceInstall</strong> also needs to be executed and as per my understanding we need to create CustomActions and for that requirement is to create functions and put them in dll file. </p>
  
  <p>I tried to look into documents of InstallShield but wasn't able to find good way or example code that i can start with to write such code. I prefer to write in C# it will be helpful if some one can guide me to write function to attach with custom actions. </p>