获取文件长度不正确的问题解决了，但是还是觉得有点不可思议

function onGetFileSize(arg_file:String):Int64;
var
  fileHandle:Integer;
begin
  fileHandle := FileOpen(arg_file,0);
  Result := getFileSize(fileHandle,nil);
  FileClose(fileHandle);
end;

FDownloadHttpCliCtrl.URL := url;
    FDownloadHttpCliCtrl.RcvdStream := TFileStream.Create(‘c:\tmp\123.zip’, fmCreate);
FDownloadHttpCliCtrl.Get;
FDownloadHttpCliCtrl.RcvdStream.Destroy;
FDownloadHttpCliCtrl.RcvdStream := nil;

function TEMSystem.onGetFileSize(arg_file:String):Int64;
var
  fileStream:TFileStream;
begin
  fileStream := TFileStream.Create(arg_file,fmShareDenyNone);
  try
    Result := fileStream.Size;
  finally
    FreeAndNil(fileStream);
  end;
end;