CaptainChaNinja

I've done a program in Delphi 7, unfortunately I need to be able to open and edit the code and run the program in Delphi 4. Everytime I try to do that I get errors. How can I possibly save a program in Delphi 7 and open it in Delphi 4?

Thanks

Lockick

I'm not a delphi expert, but in my experience making something reverse compatible after the fact is not possible without rewriting it. For the same reason ps2 games don't work on a ps1.

CaptainChaNinja

I know that reverse compatibility is normally impossible. But I am pretty sure that I have seen people do it with little effort. I just can't find anyone who knows how to do it... :mad:

OpenLoop

It's really the language designer choice wether to make it backward compatible or not. Usually, a big part of a language stays the same but the "new features" is what makes a program incompatible with older versions.
this might not help but this guy has delphi 4 to 3 converter:
http://www.drbob42.com/tools/convert3.htm

Scorpions4ever

It's very hard actually. Reason is because a lot of components have extra properties and such. Especially between Delphi 7 and Delphi 6. Delphi 5 and Delphi 4 components had similar properties, but Delphi 4 was a radical step up from Delphi 3 and IIRC the dfm file format even changed a bit between a couple of versions.

If you do open a Delphi 7 project in Delphi 4, the editor is probably going to complain that such-and-such property does not exist. You could tell it to ignore the error and delete all references to the property from the DFM file. If you're lucky, the non-existant properties aren't referenced in your code and it may compile (though the forms may look funny). If you're unlucky, then you need to fix the code to compile it on Delphi 4.