API Delphi

unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;
type
TForm1 = class(TForm)
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
function GetCurrentUserName: string;
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
function TForm1.GetCurrentUserName: string;
const
cnMaxUserNameLen = 254;
var
sUserName: string;
dwUserNameLen: DWORD;
begin
dwUserNameLen := cnMaxUserNameLen - 1;
SetLength(sUserName, cnMaxUserNameLen);
GetUserName(PChar(sUserName), dwUserNameLen);
SetLength(sUserName, dwUserNameLen);
Result := sUserName;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
ShowMessage(GetCurrentUserName);
end;
end.