qml

问题 I am using Qt 5.4.1. I have made a custom slider element to be used in other qml components like so: Slider.qml import QtQuick 2.4 import QtQuick.Controls 1.3 import QtQuick.Controls.Styles 1.3 Item { id: root width: 150 height: 30 property int val: slider.value property int maxVal: slider.maximumValue property int minVal: slider.minimumValue property int step: slider.stepSize Slider { id: slider anchors.margins: 20 stepSize: step maximumValue: maxVal minimumValue: minVal style: customStyle /

问题 I am using Qt 5.4.1. I have made a custom slider element to be used in other qml components like so: Slider.qml import QtQuick 2.4 import QtQuick.Controls 1.3 import QtQuick.Controls.Styles 1.3 Item { id: root width: 150 height: 30 property int val: slider.value property int maxVal: slider.maximumValue property int minVal: slider.minimumValue property int step: slider.stepSize Slider { id: slider anchors.margins: 20 stepSize: step maximumValue: maxVal minimumValue: minVal style: customStyle /

问题 I am using Qt 5.4.1. I have made a custom slider element to be used in other qml components like so: Slider.qml import QtQuick 2.4 import QtQuick.Controls 1.3 import QtQuick.Controls.Styles 1.3 Item { id: root width: 150 height: 30 property int val: slider.value property int maxVal: slider.maximumValue property int minVal: slider.minimumValue property int step: slider.stepSize Slider { id: slider anchors.margins: 20 stepSize: step maximumValue: maxVal minimumValue: minVal style: customStyle /

问题 changing the style of a component, seems to replace all the features of the default style. is there a way to change only one feature? For example, suppose i want a red button; import QtQuick 2.7 import QtQuick.Controls 1.4 import QtQuick.Controls.Styles 1.4 ApplicationWindow { visible: true width: 640 height: 480 Button { height: 200 width: 200 text: "Press me" style: ButtonStyle { // changes background but also throws away everything else // in standard button style background: Rectangle {

问题 How can I use a C++ class variable in QML file in Qt. I want to set a variable based on Q_OS_Android in c++ file and evaluate a condition in QML file. How will this be possible? 回答1: You have to declare the variable as property in your header file and register the class with qml in your main. Here is an example for a class Foo and a variable QString var: class Foo : ... { Q_OBJECT Q_PROPERTY(QString var READ getVar WRITE setVar NOTIFY varChanged) public: Foo(); ~Foo(); QString getVar() const

问题 I have QAbstractListModel based model... class RecordModel : public QAbstractListModel { ... }; QQmlContext *ctxt = engine.rootContext(); ctxt->setContextProperty("recordModel", &model); // QML recordModel.get(0).name // now work How to get a model data by index and role name? ... Solution : // C++ class RecordModel : public QAbstractListModel { Q_OBJECT Q_ENUMS(Roles) public: // ... Q_INVOKABLE QVariant data(int i, int role) const { return data(index(i, 0), role); } }; // QML recordModel

问题 If QML is used for GUI and Java for developing API for a linux based device,How to interface QML with Java? 回答1: One approach for cross platform integration is using web service. I would probably expose my Java code as a RESTful web service (See JAX-RS) and invoke it from QML using XMLHttpRequest. It's also worth mentioning Java GUI library such as swing / JavaFX has cross platform capability, so it should still run on Linux (and whichever platform runs Java). You might not need to write QML

问题 I have QAbstractListModel based model... class RecordModel : public QAbstractListModel { ... }; QQmlContext *ctxt = engine.rootContext(); ctxt->setContextProperty("recordModel", &model); // QML recordModel.get(0).name // now work How to get a model data by index and role name? ... Solution : // C++ class RecordModel : public QAbstractListModel { Q_OBJECT Q_ENUMS(Roles) public: // ... Q_INVOKABLE QVariant data(int i, int role) const { return data(index(i, 0), role); } }; // QML recordModel

问题 I'm trying to create a simple ListView that I can use to browse the file system, using QFileSystem . First, I tried to use code I've found that worked for QDirModel: main.qml: ListView { id: list width: 300 height: 500 model: DelegateModel { model: myFileModel delegate: Text{ id: txt text: fileName MouseArea { anchors.fill: parent onClicked: { //Switch directory when clicked list.model.rootIndex = list.model.modelIndex(index); } } } } main.cpp: int main(int argc, char *argv[]) { QApplication

问题 I'm trying to change Image with Pushbutton (GPIO PINs) stored inside a folder using QML with PyQt5 Python Code: from gpiozero import Button from signal import pause from PyQt5.QtCore import * from PyQt5.QtGui import * from PyQt5.QtQml import * import os, time, sys def btn_pressed(): global r return lambda: r.setProperty("source", "/home/pi/Desktop/example/sample/img/img1.jpg") button1 = Button(20) myApp = QGuiApplication([]) myEngine = QQmlApplicationEngine() directory = os.path.dirname(os