[Assistant]

для CM_MOUSEENTER и CM_MOUSELEAVE, я лет много очень назад писал для себя такой компонент:

Код:

unit UComp;

interface

uses Messages, ExtCtrls, Controls, Classes;

type
TUImage = class(TImage)
  private
    FOnMouseLeave: TNotifyEvent;
    FOnMouseEnter: TNotifyEvent;
    procedure CMMouseEnter(var Message: TMessage); message CM_MOUSEENTER;
    procedure CMMouseLeave(var Message: TMessage); message CM_MOUSELEAVE;
  published
    property OnMouseLeave: TNotifyEvent read FOnMouseLeave write FOnMouseLeave;
    property OnMouseEnter: TNotifyEvent read FOnMouseEnter write FOnMouseEnter;
  end;

procedure Register;

implementation

procedure TUImage.CMMouseEnter(var Message: TMessage);
begin
  if Assigned(FOnMouseEnter) then
    FOnMouseEnter(Self);
end;

procedure TUImage.CMMouseLeave(var Message: TMessage);
begin
  if Assigned(FOnMouseLeave) then
    FOnMouseLeave(Self);
end;

procedure Register;
begin
  RegisterComponents('USoft', [TUImage]);
end;
 
end.