Stored classes identified by integer - how to get type base on number?

[WojTec]

I'm storing in stream classes fields values (each class has SaveToStream/LoadFrom strem methods). Now for example if I need load from file these classes to object I'm doing:

Delphi-Quellcode:

case AType of
  0: TFirstClass.Create.LoadFromStream;
  1: TAnotherClass.Create.LoadFromStream;
  // ........
end;

This was good (but yes - lame) when was small set of classes. Now I have many ones and this method is also annoying when need to update.

Is possible map number to class type:

Delphi-Quellcode:

function GetType(AType: Int32): TBaseClass;
begin
  // ?????????????????
end;

and do

GetType(AType).Create.LoadFromStream ;

[Aphton]

You could probably try this out (depending on your Delphi Version)

Delphi-Quellcode:

type
  TClassEnum = (ceFirstClass, ceAnotherClass{, ...}); // ...

  TBaseClass = class of TBase;  // TBase is your base class (TFirstClass and TAnotherClass inherit from TBase!)

const
  cClassEnumTypes: Array[TClassEnum] of TBaseClass = (TFirstClass, TAnotherClass{, ...});

// AType: TClassEnum;
var
  Instance: TBase;
begin
  Instance := cClassEnum[AType].Create;
  Instance.LoadFromStream; 
  {...}
end;

[WojTec]

Thanks. I also tried with metaclasses and for now is working, let's see what in more complicated structure