为什么自定义过程，出错。说[Error] Unit2.pas(29): Undeclared identifier: 'NMFTP1'unit Unit2;

Question

procedure a();
begin
  Form2.NMFTP1.port := 21;
end;

Answer 1

procedure a();
begin
  Form2.NMFTP1.port := 21;
end;

Answer 2

改成这样interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, Psock, NMFtp;
type
TForm2 = class(TForm)
NMFTP1: TNMFTP;
private
//加上这句
  procedure a();
{ Private declarations }
public
{ Public declarations }
procedure a();
end;
var
Form2: TForm2;
implementation
{$R *.dfm}
//改成这样
procedure TForm2.a();
begin
NMFTP1.port=21
end;
end. 

Answer 3

public
{ Public declarations }
//此句不要
procedure a();
end;

Answer 4

procedure Tform2.a();////我改了这里
begin
NMFTP1.port=21
end;
end.