General and Desktop

Your string have "+02:00" in it so it is not an UTC time. //This is not Qt::UTC but Qt::OffsetFromUTC because of the "+02:00" QDateTime::fromString("2020-10-14T21:22:24+02:00", Qt::ISODate); If you want an UTC time QDateTime utcDateTime = QDateTime::fromString(utcDateTimeString, Qt::ISODate).toUTC(); I'm not familiar with toLocalDateTime() in java, but I think toLocalTime() might be not quite the same with it. It will convert the datetime to your system's locale time. Anyway if you want to convert it to Timezone "Europe/Berlin". QDateTime localDateTime = utcDateTime.toTimeZone(QTimeZone("Europe/Berlin")); As I tested, you'll get "2020-10-14 21:22:24" for "Europe/Berlin" time, the same as "+02:00", because of the DST. If you change the month to November QString dateTimeString = "2020-11-14T21:22:24+02:00"; QDateTime berlinDateTime = QDateTime::fromString(dateTimeString , Qt::ISODate).toTimeZone(QTimeZone("Europe/Berlin")); Then you'll get "2020-11-14 20:22:24"

@SPlatten Then I think I would at least read the proposed solutuon in, say, https://stackoverflow.com/a/35003672/489865 So one thing you can do is shm_open(..., O_RDWR) in the parent and set up a writable mapping for the parent before closing the handle, then shm_open(..., O_RDONLY) to get a read-only file handle which you will pass to the children I do not know how QSharedMemory operates, but if it indeed leverages this shm_... approach it may be relevant. I will keep quiet now, as I know no more than this....

Hi, Beside the good points of @JonB, you should also add which version of Qt you are using as well as the platform you are running your application on.

@Pham-Hoang Since no one else has replied: if you connect some device to your phone, do you have to do something to give permission to access that device to individual applications under Android?

Which version of Qt are you running ?

@JKSH You know, even though I use event filters all the time, for some reason I didn't think about using them here. But obviously that's a better way of accomplishing this than subclassing QApplication. And based on the doc excerpt you posted, it sounds like posting an event with very high priority is what I want.

Thanks to JonB I have now managed to get things working as I want.

You can't directly apply your hover background to widgets that are not being hovered. One thing you can do is to use a dynamic property and set it to all the widgets when you entering the main one and change its value when moving out of it.

Hi, You cannot just replace OpenSSL 1.0 with 1.1. The 1.1 release is not backward compatible. Furthermore, OpenSSL 1.1 support has started with Qt 5.10.0.

Close project in qtcreator

For anyone interested: the app and my dll were using different qt library versions.

@HB76 said in Error converting double to int: It was just that Qt didn't showed the real value of a even with this output format QString::number(a,'g',16) FGS. Count the number of digits. Yes, that is all digits, not just the ones after the decimal place, as per the documentation: For the 'g' and 'G' formats, the precision represents the maximum number of significant digits (trailing zeroes are omitted). Is 16 enough?

Figured it out finally. The original compiler from rpi toolchain didn't work for some reason, and my own compiler was built without --enable-multiarch Adding this parameter to gcc configure script finally solved the problem.

@Gregor_-15 You should change your real-life name to not have an accent ;-)

This situation resolved itself for unknown reasons.

@Creatorczyk said in The best communication protocol for project: transfer of large amounts of data such as camera data (openCV) ... I would like to do it mainly with the Qt and wiringPi library Those two requirements seem not to be related, I mean I don't expect you will use the wiringPi library to drive the acquisition of camera data, right? As @SGaist suggested, you may want to consider ROS, especially ROS2. And keep in mind that data acquisition (i.e. using RPi + wiringPi) is separated from robot control and actuation.

I'm slowly starting to get a better understanding of how to accomplish what I need. I managed to correctly open the editor and override the actual "double click" functionality I was originally asking about. It is simple, but my mistake was thinking the double click functionality was just a double click... it actually runs the default item list in the task menu that appears when you right click the widget in the designer. Anyways, anyone looking to "override" the designers "double click" functionality on custom widgets you need to add a custom QDesignerTaskMenuExtension to your custom widget. Then you can have the window that opens up set the tables columns and column properties of your widget. Once I understood the idea, it took me like 5 minutes to implement (it looks scarier than it is). Qt has a pretty good example of this located here: https://doc.qt.io/qt-5/qtdesigner-taskmenuextension-example.html Now I just have to figure out how to apply the results of my popup to the .ui file....