unitfrmmain.pas

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unit unitFrmMain;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    DriveComboBox1: TDriveComboBox;
    DirectoryListBox1: TDirectoryListBox;
    FileListBox1: TFileListBox;
    Label1: TLabel;
    Button2: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
    function FileLocked(Fn: string): Boolean;
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

{ TForm1 }






procedure TForm1.Button1Click(Sender: TObject);

begin

  if not FileLocked(filelistbox1.FileName) then
    Showmessage('文件已被锁定,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; //独占方式打开，其他程序不能再打开该文件
  Drive := UpperCase(Fn[1]);    //取出盘符
  Struct.fFixedDisk := Ord(Drive <> 'A'); //判断是否是硬盘
  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; //锁定文件
      Showmessage(SysErrorMessage(GetLastError)); //显示错误原因
    end
  else
    Result := False;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
   close;
end;

end.