判断文件是否正在使用

// 判断文件是否正在使用
function IsFileInUse(FName: string): Boolean;
var
HFileRes: HFILE;
begin
Result := False;
if not FileExists(FName) then
  Exit;
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
  CloseHandle(HFileRes);
end;

{ 功能说明：查找一个路径下的所有文件。
参数：path:路径, filter:文件扩展名过滤, FileList:文件列表, ContainSubDir:是否包含子目录}
procedure FindFileList(Path,Filter:string;FileList:TStrings;ContainSubDir:Boolean);
var
FSearchRec,DSearchRec:TSearchRec;
FindResult:shortint;
begin
FindResult:=FindFirst(path+Filter,sysutils.faAnyFile,FSearchRec);

try
while FindResult=0 do
begin
  FileList.Add(FSearchRec.Name);
  FindResult:=FindNext(FSearchRec);
end;
 
if ContainSubDir then
begin
  FindResult:=FindFirst(path+Filter,faDirectory,DSearchRec);
  while FindResult=0 do
  begin
   if ((DSearchRec.Attr and faDirectory)=faDirectory)
    and (DSearchRec.Name<>'.') and (DSearchRec.Name<>'..') then
    FindFileList(Path,Filter,FileList,ContainSubDir);
    FindResult:=FindNext(DSearchRec);
  end;
end;
finally
  FindClose(FSearchRec);
end;
end;
// 取文件夹文件数
function GetDirFiles(Dir: string): Integer;
var
sr: TSearchRec;
fr: Integer;
begin
Result := 0;
fr := FindFirst(AddDirSuffix(Dir) + '*.*', faAnyFile, sr);
while fr = 0 do
begin
  if (sr.Name <> '.') and (sr.Name <> '..') then
   Inc(Result);
  fr := FindNext(sr);
end;
FindClose(sr);
end;