Используйте следующий код, и вы избавитесь от изменения размера курсора мыши.
unit Unit1;
interface
uses
Windows, Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.Dialogs;
type
TForm1 = class(TForm)
private
{ Private declarations }
public
{ Public declarations }
protected
procedure CreateParams(var Params: TCreateParams); override;
procedure WMNCHitTest(var Message: TWMNCHitTest); message WM_NCHITTEST;
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
procedure TForm1.CreateParams(var Params: TCreateParams);
begin
inherited;
Params.Style := Params.Style or WS_THICKFRAME;
end;
procedure TForm1.WMNCHitTest(var Message: TWMNCHitTest);
begin
inherited;
with Message do begin
Result := HTCLIENT;
end;
end;
end.