createFile鎖定且會closehandle刪除

  hfile := CreateFile('C:\TWO.TXT', // open TWO.TXT
    GENERIC_WRITE,        // open for writing 
    0,        // do not share 
    0,        // no security
    OPEN_ALWAYS,        // open or create
    FILE_FLAG_DELETE_ON_CLOSE,//FILE_ATTRIBUTE_NORMAL,        // normal file
    0);        // no attr. template




unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    Button4: TButton;
    Button5: TButton;
    Button6: TButton;
    procedure Button6Click(Sender: TObject);
    procedure Button5Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
     hfile:THandle;

  public
    { Public declarations }
  end;

  FileHeader = packed record            //25 bytes
  uid                 : int64;
  mode                : array[1..5] of Char;     //模式
  begin_time          : TDateTime;      //開始錄影時間
  end_time            : TDateTime;      //結束錄影時間
  total_frame         : DWord;          //總共Frame 0~65535
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}


function IsFileInUse(FileName: TFileName): Boolean;
var   
  HFileRes: HFILE;
begin   
    Result := False;
    if not FileExists(FileName) then Exit;   
    HFileRes := CreateFile(PChar(FileName),   
        GENERIC_READ or GENERIC_WRITE,   
        0,   
        nil,   
        OPEN_EXISTING,   
        FILE_ATTRIBUTE_NORMAL,   
        0);   
    Result := (HFileRes = INVALID_HANDLE_VALUE);   
    if not Result then   
        CloseHandle(HFileRes);   
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  uidHeader : int64;
  BytesRead : Cardinal;      //讀寫用參數
begin
  hfile := CreateFile('C:\TWO.TXT', // open TWO.TXT
    GENERIC_READ,        // open for READ 
    0,        // do not share 
    0,        // no security
    OPEN_ALWAYS,        // open or create
    FILE_FLAG_DELETE_ON_CLOSE,//FILE_ATTRIBUTE_NORMAL,        // normal file
    0);        // no attr. template

   ReadFile(hFile, uidHeader, SizeOf(uidHeader), BytesRead, nil);
   if uidHeader=23342542 then
    caption :='good';
   
   //ShowMessage(buf);
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  caption := booltostr(IsFileInUse('C:\TWO.TXT'));
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
  closehandle(hfile);
end;

procedure TForm1.Button4Click(Sender: TObject);
var
  a_fo : TSTReam;
  h : FileHeader;
begin
  a_fo:=TFileStream.Create('C:\TWO.txt',fmCreate);
  h.uid := 23342542;
  lstrcpy(@h.mode[1], pchar('abcde'));
  a_fo.Write(h, sizeof(h));
  a_fo.free;
end;

procedure TForm1.Button5Click(Sender: TObject);
var
  a_fo : TSTReam;
  h : FileHeader;
  z : int64;
begin
  a_fo:=TFileStream.Create('C:\TWO.txt',fmOpenRead);
  a_fo.Position := 0;
  a_fo.Read(h, sizeof(h));
  z:= h.uid;
  a_fo.free;

end;

procedure TForm1.Button6Click(Sender: TObject);
var
  uidHeader : int64;
  BytesRead, BytesWrite : Cardinal;      //讀寫用參數
  pBuf:array[0..1024-1]of   byte;
  nFileSize : integer;
begin
  hfile := CreateFile('C:\BT626.pdf', // open TWO.TXT
    GENERIC_WRITE,        // open for writing 
    0,        // do not share 
    0,        // no security
    OPEN_ALWAYS,        // open or create
    FILE_ATTRIBUTE_NORMAL,//FILE_ATTRIBUTE_NORMAL,        // normal file
    0);        // no attr. template
   nFileSize:=   GetFileSize(hfile,nil);

   caption := inttostr(nFileSize);
   
   ReadFile(hFile, pBuf, nFileSize, BytesRead, nil);
   SetFilePointer(hFile,0,nil,FILE_End);
   WriteFile(hFile,pBuf,nFileSize,BytesWrite,nil);
   closehandle(hfile);
end;

end.