how do i UpdateUI in a Callback which is non-mainThread & non-QtThread?

[opengpu]

@aha_1980 just a callback funtion in windows dev, but that callback is returned from a 3rdParty DLL which use COM

[aha_1980]

@opengpu

you didn't answer my question.

how does the callbacks function signature look like?

[opengpu]

@aha_1980
WINAPI Callback(const Data& data)
{
//here is not mainThread; so i have to pass the data by value to the slot which is in mainThread; or i use mutex & save data to m_data, and then in slot mainThread getData also with mutex protect thread-safety
}

[opengpu]

is this a good way to emit signal in the non-thread non-qt Callback function?

WINAPI Callback(const Data& data)
{//here is not mainThread; so i have to pass the data by value to the slot which is in mainThread; or i use mutex & save data to m_data, and then in slot mainThread getData also with mutex protect thread-safety
    emit g_qtObj->mySignal();
}

class QtObj : public QObject
{
Q_OBJECT
signals:
    void mySignal();
}
QtObj g_obj;
QtObj* g_qtObj = &g_obj;

[SGaist]

Use QMetaObject::invokeMethod

[jsulm]

@opengpu said in how do i UpdateUI in a Callback which is non-mainThread & non-QtThread?:

g_qtObj->emit mySignal();

should be

g_qtObj->mySignal();

[opengpu]

@jsulm thanks

[opengpu]

@SGaist ```
WINAPI Callback(const Data& data)
{//here is not mainThread; so i have to pass the data by value to the slot which is in mainThread; or i use mutex & save data to m_data, and then in slot mainThread getData also with mutex protect thread-safety
//emit g_qtObj->mySignal();
QMetaObject::invokeMethod(g_pQtMainWindow, slotDoSth, Qt::QueuedConnection);
}

like this? use invokeMethod instead of emit signal ?

[SGaist]

Why do you have a global Qt object ?
What makes you define your Callback method like that ?

[opengpu]

why QMetaObject::invokeMethod pass custom-type called Twice custom-type's copy constructor...
https://forum.qt.io/topic/102915/qmetaobject-invokemethod-pass-custom-type-called-twice-custom-type-s-copy-constructor