Delphi Compiler Error
E2228 A dispinterface type cannot have an ancestor interface
Reason for the Error & Solution
An interface type specified with dispinterface cannot specify an ancestor interface.
program Produce;
type
IBase = interface
end;
IExtend = dispinterface (IBase)
['{00000000-0000-0000-0000-000000000000}']
end;
begin
end.
In the example above, the error is caused because IExtend attempts to specify an ancestor interface type.
program Solve;
type
IBase = interface
end;
IExtend = dispinterface
['{00000000-0000-0000-0000-000000000000}']
end;
begin
end.
Generally there are two solutions when this error occurs: remove the ancestor interface declaration, or change the dispinterface into a regular interface type. In the example above, the former approach was taken.
