当dcu存在时，Delphi是否在编译时需要dfm？

Question

I always assumed that the dcu file is all that is needed at compile time. At least, the source files (pas and dfm) should not be required.

I have the following situation:

• A Delphi application with two units that each contain a form:
  • UMain contains form TMain
  • USubForm contains form TSubForm
• USubForm is in the uses clause of UMain
• After I compile this program, I removed USubForm.pas and USubForm.dfm and replaced them by the compiled USubForm.dcu.
• Compilation now results in an error: DCC : error : E1026 File not found: 'USubForm.dfm'
• Note that if I only remove USubForm.pas (but leave USubForm.dfm file in place next to USubForm.dcu), the compilation works.

I don't understand. I thought the dcu file would be all I need (ie it's the compiled version of the pas + dfm file).

I'm using Delphi XE2 (we should be upgrading soon, but I don't think this is relevant for my question).

PS Some context: I'm trying to setup a continuous integration system for our in-house Delphi libraries and applications. I'd like to be able to compile applications without needing the source files of the libraries.

Answer 1

Yes, you need the DFM file when you link your project. It's treated like a resource file. As I recall, it's not required when compiling.