unitfrmmain.pas

《Delphi百例》源码?禗elphi百例》源码

unit unitFrmMain;

interface

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

type
  TForm1 = class(TForm)
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
    function FileLocked(Fn: string): Boolean;
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

{ TForm1 }



procedure TForm1.FormCreate(Sender: TObject);
begin
  if not FileLocked('test.txt') then
    Showmessage('文件已经被加锁,无法打开');
end;

function Tform1.FileLocked(Fn: string): Boolean;
var
  I: Integer;
  Struct: TOfStruct;
  Style: Cardinal;
  Hdl: Hfile;
  Drive: string;
begin
  Style := OF_Share_Exclusive; //排它方式打开
  Drive := UpperCase(Fn[1]);
  Struct.fFixedDisk := Ord(Drive <> 'A'); //判断是否是硬盘
  Struct.cBytes := SizeOf(Struct);
  for I := 1 to Length(Fn) do
    Struct.szPathName[I - 1] := Fn[I];
  Struct.szPathName[I] := Chr(0); //填充文件名
  Hdl := OpenFile(Pchar(Fn), Struct, Style);
  if Hdl = HFILE_ERROR then
    begin
      Result := True; //文件被锁定
      Showmessage(SysErrorMessage(GetLastError)); //显示错误原因
    end
  else
    Result := False;
end;


end.