How do you initialise a const array of TGUID from Interface type data, in Delphi?

Question

I want to initialise an array like this -

Const MyArray : Array[0..0] Of TGUID = (IInterface);

But it results in -

[DCC Error] Test.pas(10): E2010 Incompatible types: 'TGUID' and 'string'

So to see what would happen I tried this -

Const MyArray : Array[0..0] Of String = (IInterface);

Which results in this!

[DCC Error] Test.pas(10): E2010 Incompatible types: 'string' and 'TGUID'

How strange! Surely IInterface is one or the other, but it seems to stubbornly transform into the wrong type.

Answer 1

You can pull the GUIDs from the interface declarations and declare them as (string) constants. You can then use these constants in your interface declarations and your array constant declarations. The compiler accepts valid GUID strings where TGUID is expected. Invalid strings result in E2204 "Improper GUID syntax" compile error.

const
  MyGuid1 = '{99BDAB12-B1B6-41B0-9BF1-2C1DB3D8EC70}';
  MyGuid2 = '{8C7CD303-8D81-469B-99ED-E1F163E9036F}';

type
  IMyInterface1 = interface
    [MyGuid1]
  end;

  IMyInterface2 = interface
    [MyGuid2]
  end;

const
  MyArray: array[0..1] of TGUID = (MyGuid1, MyGuid2);

Answer 2

If you use a const array you have to set it up with const values like this:

const GuidArray: array[0..0] of TGuid=
  ('{84DBCC66-72AA-4806-AE28-B55FC5B83FC8}');