mmapform.pas

Delphi高级开发指南是开发程序的好帮手

unit MMapForm;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls;

type
  TForm1 = class(TForm)
    BtnWrite: TButton;
    EditWrite: TEdit;
    BtnRead: TButton;
    EditRead: TEdit;
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
    procedure BtnWriteClick(Sender: TObject);
    procedure BtnReadClick(Sender: TObject);
  private
    hMapFile: THandle;
    MapFilePointer: Pointer;
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.FormCreate(Sender: TObject);
begin
  hMapFile := CreateFileMapping (
    $FFFFFFFF, // file handle ... or memory
    nil, // security
    Page_ReadWrite, // access rights
    0, // high memory size
    10000, // low memory size
    'DdhDemoMappedFile'); // mapped file name
  if hMapFile <> 0 then
    MapFilePointer := MapViewOfFile (
      hMapFile, // handle returned above
      File_Map_All_Access, // access rights
      0, 0, 0) // access the entire mapped file
  else
    ShowMessage ('hMapFile = 0');
  if MapFilePointer = nil then
    ShowMessage ('MapFilePointer = nil');
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  UnMapViewOfFile (MapFilePointer);
  CloseHandle (hMapFile);
end;

procedure TForm1.BtnWriteClick(Sender: TObject);
begin
  StrCopy (PChar (MapFilePointer),
    PChar (EditWrite.Text));
end;

procedure TForm1.BtnReadClick(Sender: TObject);
var
  S: string;
begin
  S := PChar (MapFilePointer);
  EditRead.Text := S;
end;

end.