检查文件是否在Delphi中打开

TTextRec(txt).Mode为您提供以下模式:

55216 = closed
55217 = open read
55218 = open write

fmClosed = $D7B0;
fmInput  = $D7B1;
fmOutput = $D7B2;
fmInOut  = $D7B3;

有关详细信息,请在系统单元中搜索TTextRec。

function IsFileInUse(fName: string) : boolean;
var
  HFileRes: HFILE;
begin
  Result := False;
  if not FileExists(fName) then begin
    Exit;
  end;

  HFileRes := CreateFile(PChar(fName)
    ,GENERIC_READ or GENERIC_WRITE
    ,0
    ,nil
    ,OPEN_EXISTING
    ,FILE_ATTRIBUTE_NORMAL
    ,0);

  Result := (HFileRes = INVALID_HANDLE_VALUE);

  if not(Result) then begin
    CloseHandle(HFileRes);
  end;
end;

这很好:

function IsOpen(const txt:TextFile):Boolean;
const
  fmTextOpenRead = 55217;
  fmTextOpenWrite = 55218;
begin
  Result := (TTextRec(txt).Mode = fmTextOpenRead) or (TTextRec(txt).Mode = fmTextOpenWrite)
end;

bFileIsOpen . 无论文件在何处打开,都要设置 bFileIsOpen := true 然后,当您需要知道文件是否打开时,只需测试这个变量;例子: if (bFileIsOpen) then Close(datafile);

filenotopen 如果有可能的话,我会改变路线

Result := (HFileRes = INVALID_HANDLE_VALUE);

Result := NOT (HFileRes = INVALID_HANDLE_VALUE);

我还删除了行“if not(Result)then begin”(以及“end”),这样它总是关闭句柄或后续赋值,并读取give errors

我现在这样称呼它

if filenotopen(filename) then 
  begin
    assignfile(f,filename);
    reset(f)
    etc;
  end
else
  message('file open by a different program')