child.pas

这是一个DELPHI7应用案例开发篇有配套程序种子光盘

unit Child;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, Menus, StdCtrls, ComCtrls, IniFiles;

type
  TfrmChild = class(TForm)
    RichEdit1: TRichEdit;
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure RichEdit1Change(Sender: TObject);
    procedure FormCloseQuery(Sender: TObject; var CanClose: Boolean);
    procedure FormActivate(Sender: TObject);
  private
    FIsModified: Boolean;
    FIsNamed: Boolean;
    FFileName: String;
    procedure SetIsModified(const Value: Boolean);
    procedure SetIsNamed(const Value: Boolean);
    procedure SetFileName(const Value: String);
    { Private declarations }
  public
    constructor Create(Owner:TComponent);override;
    property IsModified:Boolean read FIsModified write SetIsModified;
    property IsNamed:Boolean read FIsNamed write SetIsNamed;
    property FileName:String read FFileName write SetFileName;

    procedure LoadFromFile(AFileName:String);
    procedure SaveToFile(AFileName:String);
  end;

var
  frmChild: TfrmChild;

implementation

uses Main;

{$R *.dfm}

constructor TfrmChild.Create(Owner: TComponent);
begin
    inherited;
    FIsModified := False;
    FIsNamed := False;
    FFileName := '';
end;

procedure TfrmChild.FormClose(Sender: TObject; var Action: TCloseAction);
begin
    Action := caFree;
end;

procedure TfrmChild.LoadFromFile(AFileName: String);
begin
    RichEdit1.Lines.LoadFromFile(AFileName);
    IsNamed := True;
    FileName := AFileName;
    Caption := AFileName;
    IsModified := False;
end;

procedure TfrmChild.SaveToFile(AFileName: String);
begin
    IsNamed := True;
    FileName := AFileName;
    RichEdit1.Lines.SaveToFile(AFileName);

    IsModified := False;
end;

procedure TfrmChild.SetFileName(const Value: String);
begin
    FFileName := Value;
    Caption := Value;
end;

procedure TfrmChild.SetIsModified(const Value: Boolean);
begin
  FIsModified := Value;
end;

procedure TfrmChild.SetIsNamed(const Value: Boolean);
begin
  FIsNamed := Value;
end;

procedure TfrmChild.RichEdit1Change(Sender: TObject);
begin
    IsModified := True;
    frmMain.UpdateStatusBar;
end;

procedure TfrmChild.FormCloseQuery(Sender: TObject; var CanClose: Boolean);
var
    res : Word;
begin
    if IsModified then
    begin
        res := MessageDlg('File '+FileName+' was modified. Save it now?',
            mtWarning, [mbYes,mbNo,mbCancel], 0);

        case res of
        mrYes:
            begin
                RichEdit1.Lines.SaveToFile(FileName);
                CanClose := True;
            end;
        mrNo:
            CanClose := True;
        mrCancel:
            CanClose := False;
        end;
    end
    else
        CanClose := True;
end;

procedure TfrmChild.FormActivate(Sender: TObject);
begin
    frmMain.UpdateStatusBar;
end;

end.