qt5

问题 I am using Qt 5.7 on Ubuntu 16 LTS machine. I get this error: (.qtversion[qt_version_tag]+0x0):-1: error: undefined reference to `qt_version_tag' This error comes only when I use SDL libraries. 回答1: I realize this is an old thread but you may be able to avoid it by defining QT_NO_VERSION_TAGGING; that is, by passing the option: -DQT_NO_VERSION_TAGGING to gcc. 来源： https://stackoverflow.com/questions/39871879/why-do-i-get-this-error-undefined-reference-to-qt-version-tag

问题 I have a server running Ubuntu 12.04 LTS. I would like to put the server to use building Qt5 for the Android ARMv6 platform. How does one go about doing this on a headless server? 回答1: The steps necessary for compiling Qt5 for Android on Ubuntu 12.04 LTS are described below. For the sake of convenience, I will assume that all of the commands below are run in the directory /opt/qt5-android . You will need to adjust the paths accordingly if this is not the case. First you will need to make sure

问题 How to show percentage in Qt Pie charts on chart like this? 回答1: To do this task you have to enable to make the labels visible and place the position as LabelInsideHorizontal, in the following code the solution is shown. series->setLabelsVisible(); series->setLabelsPosition(QPieSlice::LabelInsideHorizontal); for(auto slice : series->slices()) slice->setLabel(QString("%1%").arg(100*slice->percentage(), 0, 'f', 1)); PyQt5: import sys from PyQt5 import QtCore, QtGui, QtWidgets, QtChart if __name

问题 In a QWidget derived class object with implemented tabletEvent(QTabletEvent *event) and mousePressEvent(QMouseEvent *event), the mousePressEvent gets called every time tabletEvent gets called with type TabletEvent::TabletPress. According to the Qt documentation, this should not happen: The event handler QWidget::tabletEvent() receives TabletPress, TabletRelease and TabletMove events. Qt will first send a tablet event, then if it is not accepted by any widget, it will send a mouse event .

问题 I'm struggling with the task to generate a binary deployed with the required shared libraries. I created a "hello world" for Qt 5.12 plugins, the app runs as expected in my Ubuntu 18.04 machine, but make install gives an error. I tried the fixup_bundle() approach for resolving dependencies. obs.: I never done this before, I'm new to cmake . cmake_minimum_required(VERSION 3.17) project(plug-use LANGUAGES CXX) set(PROJECT_VERSION_MAJOR 1) set(PROJECT_VERSION_MINOR 0) set(PROJECT_VERSION_PATCH 0

问题 As the title says I am trying to have my QGraphicsView blinking 1 second in red, 1 second in green and 1 second in blue and after that the loop start over again. After doing a lot of research in the past couple of days I didn't have a lot of luck as the main problem is that I am not sure I need to subclass QGraphicsView to obtain the effect I am looking for. I came across some references that I inserted below saying that for this type of problems QPropertyAnimation seems to be the right

问题 This question follow a problem on cross compilation: https://stackoverflow.com/posts/61433338/edit I tried to compile Qt5 with gcc 8.3.0 (gnueabihf) but i get the following error while recompilling Qt5: (note this is only the command failing during configure) $/usr/local/gcc-arm-8.3-2019.03-x86_64-arm-linux-gnueabihf/bin/arm-linux-gnueabihf-g++ -mfloat-abi=hard --sysroot=/home/ftrefou/raspi/sysroot -Wl,-O1 -Wl,-rpath-link,/home/ftrefou/raspi/sysroot/usr/lib/arm-linux-gnueabihf -Wl,-rpath-link

问题 In order to shrink the problem I made a small verifiable example of a small gui. If you would like to take a glance at the code you can see it here. I have a specific string on a QLineEdit , this string is passed to a QListView via QPushButton as shown below. Those strings are choices of a QComboBox and they are very specific: 1) "[ INFO] Minimum Distance: 5", 2) "[ INFO] Minimum Distance: 10" and 3) "[ INFO] Minimum Distance: 15" The problem: How can I detect the specific QString content

问题 I am trying to display log messages from a work thread in a GUI. I am trying to follow redirect qDebug to QTextEdit It started to work fine, but I am stuck, how to program QObject::connect(otherThread, SIGNAL(debug(QString)), s_textEdit, SLOT(append(QString)), Qt::QueuedConnection); The principle I see, that one signal in the thread shall be connected to a slot in the GUI thread; but how to trigger that signal? Also, I make some logging with QDebug , but also some output to std::cerr . Can I

问题 I am trying to display log messages from a work thread in a GUI. I am trying to follow redirect qDebug to QTextEdit It started to work fine, but I am stuck, how to program QObject::connect(otherThread, SIGNAL(debug(QString)), s_textEdit, SLOT(append(QString)), Qt::QueuedConnection); The principle I see, that one signal in the thread shall be connected to a slot in the GUI thread; but how to trigger that signal? Also, I make some logging with QDebug , but also some output to std::cerr . Can I