I've been reading lots on how to trigger an application from inside a C# program (Process.Start()), but I haven t been able to find any information on how to have this new application run within a panel of my C# program. For example, I'd like a button click to open a notepad.exe WITHIN my application, not externally.
I know this is possible if the other application can attach itself to a win32 window handle. For example, we have a separate C# application that hosts a DirectX application inside one of its windows. I'm not familiar with the exact details of how this is implemented, but I think just passing the win32 Handle of your panel to the other application is enough for that application to attach its DirectX surface.
If you want to run notepad inside your app you would probably be better of with a text editor component. There's obviously a basic text box that comes with WinForms, but I suspect more advanced components that offer Notepad functionality (or better) can be found on the interweb.