Question

I have enum-type data like:

typedef enum
{
    NULLTYPE = 0U,
    ParameterGetType = 1U,
    ParameterSetType = 2U,
    ParameterStatusType  = 3U,
    EventActionType  = 4U,
    CommandType  = 5U,
    CommandGetType  = 6U,
    CommandSetType  = 7U,
    EquipmentIDGetType   = 15U,
    EquipmentIDSetType   = 16U,
    EquipmentIDStatusType = 17U,
    EventReportGetType  = 18U,
    EventReportSetType  = 19U,
    EventReportStatusType = 20U,
    PeriodicReportType = 21U,
    PeriodicReportGetType  = 22U,
    PeriodicReportSetType  = 23U,
    PeriodicReportStatusType  = 24U,
    CommandResponseType  = 25U,
    CommandResponseGetType  = 26U,
    CommandResponseSetType  = 27U,
    CommandResponseStatusType  = 28U,
    CommandResponseDeletedType  = 29U

}MessageType;

I want to save it into binary file using QByteArray and QFile::write(QByteArray),
but I don’t know the length of the data, and the ‘distribution’ of bytes’ value of the data，
(if the data is 1, will other bytes’ value be zero?)
I think it is not limited to qt, how to write the data into file?

(For short-type data (MsgItem->PIN), I will do this:)

QByteArray bytes;
bytes.append(((MsgItem->PIN)>>8) & 0xff);
bytes.append((MsgItem->PIN) & 0xff);
MsgFile->write(bytes);
MsgFile->flush();

Answer 1

Convert the enum value to a fixed-size integer (use <cstdint> and e.g. uint16_t) and do whatever byte-ordering manipulations you need.