编译多文档窗体时报错：[Error] MAIN.PAS(60): Undeclared identifier: 'TMDIChild'？

Question

不知道为什么？该怎样改？谢谢？

Answer 1

unit MAIN;interfaceuses Windows, SysUtils, Classes, Graphics, Forms, Controls, Menus,
  StdCtrls, Dialogs, Buttons, Messages, ExtCtrls, ComCtrls, StdActns,
  ActnList, ToolWin, ImgList, DB, ADODB;type
  TMainForm = class(TForm)
    MainMenu1: TMainMenu;
    File1: TMenuItem;
    mi_form: TMenuItem;
    mi_uic: TMenuItem;
    mi_sys_param: TMenuItem;
    Window1: TMenuItem;
    Help1: TMenuItem;
    N1: TMenuItem;
    FileExitItem: TMenuItem;
    WindowCascadeItem: TMenuItem;
    WindowTileItem: TMenuItem;
    WindowArrangeItem: TMenuItem;
    HelpAboutItem: TMenuItem;
    mi_ref_code: TMenuItem;
    WindowMinimizeItem: TMenuItem;
    StatusBar: TStatusBar;
    WindowTileItem2: TMenuItem;
    mi_sys_msg: TMenuItem;
    mi_err_log: TMenuItem;
    mi_action_log: TMenuItem;
    mi_sys_menu: TMenuItem;
    ADOConnection1: TADOConnection;
    adoq_max_int_key: TADOQuery;
    adoq_caption_max_int_key: TADOQuery;
    ado_conn_query: TADOConnection;
    adoq_main: TADOQuery;
    adoq_sd_uic: TADOQuery;
    dsrc_main: TDataSource;
    dsrc_sd_uic: TDataSource;
    procedure HelpAbout1Execute(Sender: TObject);
    procedure mi_formClick(Sender: TObject);
  private
    { Private declarations }
    procedure CreateMDIChild(const Name: string);
  public
    { Public declarations }
  end;var
  MainForm: TMainForm;implementation{$R *.dfm}uses CHILDWIN, about;procedure TMainForm.CreateMDIChild(const Name: string);
var
  Child: TMDIChild;  <- 此处报错
begin
  { create a new MDI child window }
  Child := TMDIChild.Create(Application);
  Child.Caption := Name;
  
end;

Answer 2

你的Tmdichild是什么啊？？？？？你有这个东东吗，并且uses他的单元了吗？

Answer 3

TMDIChild是在自动生成的CHILDWIN.pas里的，你检查一下CHILDWIN.pas的是否完整：unit CHILDWIN;interfaceuses Windows, Classes, Graphics, Forms, Controls, StdCtrls;type
  TMDIChild = class(TForm)
    Memo1: TMemo;
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
  private
    { Private declarations }
  public
    { Public declarations }
  end;implementation{$R *.dfm}procedure TMDIChild.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  Action := caFree;
end;end.