General and Desktop

Hi, The most "simple" is to downsample from 10 to 8 bit. Maybe OpenCV has better support for that kind of format and might be an alternative.

Hi, @WLOrion said in Introduction in Qwt: I didn't know this behavior of the Qwt Classes. This is nothing Qwt specific, it's part of the C++ basics. As for tutorial, there's a nice online book that is in German but the author claims that online translator should give you a good enough result in your own language.

@Taytoo said in QSharedMemory access without lock()?: That's why wondering whether osx api uses some underlying locking api? Look at the code, it's opensource.

@suslucoder It is not clear what you are trying to do here. I want to match my integer definitions to my predefines. "Match" in what sense? You have 6 variables. Does that mean each of those variables can take its own value, independent of whatever is in the others? In that case, it is not clear what the purpose of the #defines is? Especially when you write: int TM_AP_ID_PID; //it is 0 and i use it as an idex Is the value of TM_AP_ID_PID always 0? Then why do you have it in a variable? Purely at a guess, you should be considering one or both of these: Use a C++ enum. Create a 6-element array (or map) for your currently separate variables, so that you can address them via array[TM_something].

@Vladi said in [Qt Designer] PyQt5 - why does the designer add "centralWidget"?: Why? What's the purpose of that thing? Because a QMainWindow has a central widget. This widget consumes the area between menu/tool bar and status bar. This widget is used as container/parent for all the widgets you put inside your main window. What is the problem with it?

@developer_61 said in How to load QTreeView asynchrone.: how to use that thread? Start here: https://doc.qt.io/qt-5/thread-basics.html "is it possible to do that during this loading with for example an small gear?" yes

@jsulm It means - not an option for me to be used. Thx to all. Will do my own solution. Issue closed.

@JKSH ,thanks,I find that this happens when debugging, not when publishing。

@suslucoder said in How to add datas in table widget with increasing the row number: It should start to add from row 0 to the end of row count And what is the problem? Set row count via https://doc.qt.io/qt-5/qtablewidget.html#setRowCount and add your data...

@Uday-More you're forcing synchronous behavior on an asynchronous API, thats your problem. Change it to proper event driven code and also connect to the various error signals of QNetworkAccessManager and QNetworkReply

@arjun98 Did you check https://doc.qt.io/qt-5/qmediaplayer.html ? It also has signals you can use for your purpose.

As you can see from the doc, QMetaDataWriterControl is an abstract class, most of its functions are virtual. It is just an interface class and the functions need to be implemented by the media plugins. And from Qt Multimedia Backends you can see that "MetaData writer" is not a feature of media player, but recording. And it is only supported by the GStreamer plugin on Unix platform. There's QMediaRecorder::setMetaData(...) which would probably try to use this interface internally. So it's not for QMediaPlayer I think.

@jars121 said in Using Qt sockets over the internet with NAT traversal: The main issue with using a VPN, is the computers running the client application need to remain on their standard networks; I can't tunnel all network traffic through the VPN. Look up "selective routing", e.g. https://serverfault.com/questions/134753/openvpn-and-selective-routing

Seems like you are mixing compilers. What are you using to compile your program?

[Additional discussion about temporary object lifetime is forked to https://forum.qt.io/topic/125012/lifetime-of-temporary-objects ]

Strip down your program until no leak occur anymore or until it's so minimal so that you can post it here. A timer does not leak memory (and especially not that much that you notice it in a few seconds). What leak detection tool do you use?

@SPlatten said in Passing QJsonObject works, but QJsonArray doesn't ?: it isn't Java, its JavaScript and I expect the Qt API to convert the array because it does exactly that for a JavaScript object. What is the point of offering only half a solution? If JavaScript objects are processed then arrays should also be processed. Yes, you are right it is JavaScript, and JavaScript is not known as strongly typed language. There are many implicit conversion done, so awaiting that this is just working seems not really serious to me. I wish you good luke!

@Kite-R As you're asking for help you should provide a simple and small example showing the behavior instead of asking others to download something, change this and that.