使用.Show命令打开login窗体时触发Access Violation错误求助

架构老林

2026-8-16

Delphi调用Login窗体.Show触发Access Violation错误

在Delphi项目中，主窗体激活事件内执行login.Show打开独立登录窗体时，触发Access Violation错误，无法正常打开登录窗体。

主窗体激活事件代码

procedure TForm4.FormActivate(Sender: TObject);
begin
  label1.BringToFront;
  DBMatch.Enabled := false;
  DBContestants.Enabled := false;
  btncreate.Enabled := false;
  DbNav.Enabled := false;
  login.Show;
end;

Login窗体代码片段

unit login_form;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs ,StdCtrls, ExtCtrls, unit4,pngimage;

type
  Tlogin = class(TForm)
    edit_username: TEdit;
    edit_password: TEdit;
    btnlogin: TButton;
    btnForgotten: TButton;
    lUsername: TLabel;
    LPassword: TLabel;
    Imageside: TImage;
    procedure btnloginClick(Sender: TObject);
    procedure FormActivate(Sender: TObject);
  private
    { Private declarations }
  public
  end;

var
  login: Tlogin;
  password,result:string;

implementation
{$R *.dfm}
 uses dmChess_u;