建立classname，然後可以幫助判斷該classname是否關閉

註冊classname

  public
    procedure createparams(var params:tcreateparams);override;

  const
    TSFPatch729ClassName = 'abcde';

procedure TForm1.CreateParams(var Params: TCreateParams);
begin
  inherited;
  StrCopy(Params.WinClassName, _TSFPatch729ClassName);
end;

判斷classname

  const
    TSFPatch729ClassName = 'abcde';
  
  begin
    while isWindow(FindWindow(_TSFPatch729ClassName,nil)) do
    begin
      sleep(300);
    end;
  end;

檢查日期時間合不合法

procedure CheckDate(var nYear: Integer; var nMonth: Integer;
    var nDay: Integer);
begin
  //Check day
  case nMonth of
  1, 3, 5, 7, 8, 10, 12: begin
    //31 days
    if(nDay >=31) then
    begin
      //進位
      nMonth:=nMonth+1;
      nDay:=nDay-31;
      if(nMonth = 2) then
      begin
        if(nDay >= 28) then
          //還要進位
          CheckDate(nYear, nMonth, nDay);
      end
      else if(nDay >= 30) then
        //還要進位
        CheckDate(nYear, nMonth, nDay);
    end
    else if(nDay < 0) then
    begin
      //退位
      nMonth:=nMonth-1;
      //if(nMonth
    end;
    end;//break
  4, 6, 9, 11: begin
    //30 days
    end;//break
  2: begin
    if(((nYear-1900) mod 4) = 0) then
    begin
      //29 days
    end
    else
    begin
      //29 days
    end;
    end;//break
  end;
  //Check month
  if(nMonth > 12) then
  begin
    Inc(nYear);
    Dec(nMonth, 12);
  end
  else if(nMonth < 0) then
  begin
    Dec(nYear);
    nMonth:=12+nMonth;
  end;
end;
//---------------------------------------------------------------------------

procedure CheckDateTime(var nYear: Integer; var nMonth: Integer;
    var nDay: Integer; var nHour: Integer; var nMin: Integer;
    var nSec: Integer; var nMSec: Integer);
var
  a: Integer;

begin
  //Check Millisecond.
  if(nMSec >= 1000) then
  begin
    //進位
    a:=nMSec div 1000;
    nSec:=nSec+a;
    nMSec:=nMSec-a*1000;
  end
  else if(nMSec < 0) then
  begin
    //退位
    a:=nMSec div 1000;
    Inc(a);
    nSec:=nSec-a;
    nMSec:=a*1000+nMSec;
  end;
  //Check second.
  if(nSec >= 60) then
  begin
    //進位
    a:=nSec div 60;
    nMin:=nMin+a;
    nSec:=nSec-a*60;
  end
  else if(nSec < 0) then
  begin
    //退位
    a:=nSec div 60;
    Inc(a);
    nMin:=nMin-a;
    nSec:=a*60+nSec;
  end;
  //Check minute.
  if(nMin >= 60) then
  begin
    //進位
    a:=nMin div 60;
    nHour:=nHour+a;
    nMin:=nMin-a*60;
  end
  else if(nMin < 0) then
  begin
    //退位
    a:=nMin div 60;
    Inc(a);
    nHour:=nHour-a;
    nMin:=a*60+nMin;
  end;
  CheckDate(nYear, nMonth, nDay);
end;
//---------------------------------------------------------------------------

檔案的時間轉系統時間

function FileTimeToDateTime(var ft: FILETIME): TDateTime;
var
  //ft2: FILETIME;
  st: SYSTEMTIME;

begin
  Result:=0;
  if((ft.dwHighDateTime = 0) and (ft.dwLowDateTime = 0)) then
  begin
    Exit;
  end;
  //if(not FileTimeToLocalFileTime(ft, ft2)) then
  //begin
  //  Exit;
  //end;
  //if(not FileTimeToSystemTime(ft2, st)) then
  //  Exit;
  if(not FileTimeToSystemTime(ft, st)) then
    Exit;
  Result:=SystemTimeToDateTime(st);
end;

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.

判斷檔案是否被鎖住

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; 

取得磁碟剩餘空間

var
  g_sTempDriver : integer;
  DiskFreeSize : int64;
begin
  g_sTempDriver := Ord(UpperCase(g_sTempPath)[1])-64; //UpperCase(g_sTempPath)[1]某個槽
  DiskFreeSize := DiskFree(g_sTempDriver);

  //DiskFreeSize div 1024 = bytes

取得APP PATH

procedure TForm1.FormCreate(Sender: TObject);
begin
  caption := extractfilepath(ParamStr(0));
end;

避免Delphi的TDateTimePicker的onChange事件會執行二次

procedure TForm1.DateTimePicker1Change(Sender: TObject);
begin
  if (DateTimePicker1.DroppedDown) then 
    exit;
  DateTimePicker1CloseUp(sender);
end;

procedure TForm1.DateTimePicker1CloseUp(Sender: TObject);
begin
  //你不想執行二次的程式碼
end;