Syntax

type TClass = class of TObject;

Description

TClass is the root metaclass type. You can use TClass any time you need a generic class reference.

Tips and Tricks

Example

// Map class names to class references.
type
  TClassMap = class
  private
    fList: TStrings;
    function GetClass(const Name: string): TClass;
    procedure PutClass(const Name: string; Value: TClass);
  public
    procedure Add(ClsRef: TClass);
    property Classes[const Name: string]: TClass
        read GetClass write SetClass; default;
  end;

procedure TClassMap.Add(ClsRef: TClass);
begin
  // TStrings takes TObject as the associated data,
  // so cast TClass to TObject.
  fList.AddObject(ClsRef.ClassName, TObject(ClsRef));
end;

function TClassMap.GetClass(const Name: string): TClass;
begin
  Result := TClass(fList.Objects[fList.IndexOf(Name)]);
end;

procedure TClassMap.SetClass(const Name: string; Value: TClass);
var
  Index: Integer;
begin
  Index := fList.IndexOf(Name);
  if Index < 0 then
    fList.AddObject(Name, TObject(Value))
  else
    fList.Objects[Index] := TObject(Value);
end;
...
var
  Map: TClassMap;
  Cls: TClass;
...
Map.Add(TObject);
Map.Add(TComponent);
Map.Add(TForm);
Cls := Map['TButton'].ClassParent; // Cls := TButtonControl

See Also