We have a need to interoperate between one of our web apps and a Win32 app created in Delphi.
A colleague suggested using a custom protocol handler like ourcompany://something to pass information to the app.
Is this possible with Delphi (5 Enterprise), or not? If it's available in later versions, we'll look to sourcing a license for that.
Cheers!
MSDN has an article explaining the whole thing. It describes the registry entries you need to set up, and it describes the command line that Internet Explorer will use to invoke your program.
There's nothing to prevent you from writing a protocol handler in any Delphi version you want.
A custom protocol handler is a registered COM object that implements the IInternetProtocol interface.
Here http://www.doogal.co.uk/plugprot.php is some information on how to implement it in Delphi.
Yes, as a matter of fact that is exactly how the IDE Welcome page works. We register a custom protocol handler for bds://.
来源：https://stackoverflow.com/questions/2246192/can-delphi-be-used-to-create-and-handle-a-custom-protocol-handler