DeleteIfTooLarge

procedure DeleteIfTooLarge(AFileName: TFileName);
Var
  FileStream : TFileStream;
  IsTooLarge : Boolean;
begin
  if Not FileExists(AFileName) then exit;

  FileStream := TFileStream.Create(AFileName,fmOpenRead);
  try
    IsTooLarge := FileStream.Size > MaxSize;
  finally
    FileStream.Free;
  end;

  if IsTooLarge then
     DeleteFile(AFileName);
end;

 

RZFileName := ExtractFilePath(Application.ExeName)+'下發日誌.log';
    DeleteIfTooLarge(RZFileName);
    AssignFile(FLog,RZFileName);
    if FileExists(RZFileName) then
      Append(FLog)
    else
      Rewrite(FLog);