Get the value of QML Editbox from C++ - c++

Question

I have created a QtQuick application with some textboxes in QML. I want to use the value of those textboxes in my c++ code. So how can I fetch those values from C++ code?

Answer 1

It can be like:
QML file:
Item{
id: root
signal textChanged(string msg)
TextInput
{
id: inputText
anchors.horizontalCenter: root.horizontalCenter
anchors.verticalCenter: root.verticalCenter
text : ""
inputMethodHints: Qt.ImhNoPredictiveText
selectByMouse: true
onAccepted: {
inputText.focus = false;
Qt.inputMethod.hide();
root.textChanged(inputText.text);
}
}
}
ِYou can connect the signal of your qml to some slot in cpp like:
QObject::connect((QObject *)viewer.rootObject(), SIGNAL(textChanged(QString)), this, SLOT(someSlot(QString)));

Answer 2

I believe you have some C++ class which is used as a data container. You are using the QML for UI purposes. Whatever data a user enters via QML UI must be stored in the C++ container.
There are 2 ways to achieve it.
1)Create and manage objects in C++ and expose objects to QML by using setContextProperty() method
2)Create a class in C++ and register that class as a QML type to be used in QML side using qmlRegisterType function and then manage objects from QML side itselft
This example contains a Customer class which has a simple class Employee and a single data member name. This example demonstrates both ways as described above.
employee.h header file
#ifndef EMPLOYEE_H
#define EMPLOYEE_H
#include <QObject>
class Employee : public QObject
{
Q_OBJECT
Q_PROPERTY(QString name READ name WRITE setName NOTIFY nameChanged)
public:
explicit Employee(QObject *parent = 0);
QString name();
void setName(const QString &name);
signals:
void nameChanged();
public slots:
private:
QString m_name;
};
employee.cpp file
#include "employee.h"
#include <QDebug>
Employee::Employee(QObject *parent) :
QObject(parent)
{
}
QString Employee::name()
{
return m_name;
}
void Employee::setName(const QString &name)
{
if(m_name!=name)
{
m_name=name;
emit nameChanged();
qDebug()<<"C++:Name changed->"<<m_name;
}
}
main.cpp file
#include <QtGui/QGuiApplication>
#include "qtquick2applicationviewer.h"
#include <employee.h>
#include <QQmlEngine>
#include <QQmlContext>
#include <QtQml>
int main(int argc, char *argv[])
{
QGuiApplication app(argc, argv);
QtQuick2ApplicationViewer viewer;
Employee emp;
viewer.rootContext()->setContextProperty("employee",&emp);
qmlRegisterType<Employee>("CPP.Mycomponents",1,0,"Employee");
viewer.setMainQmlFile(QStringLiteral("qml/SO_GetValueOfQMLEditboxFromCpp/main.qml"));
viewer.showExpanded();
return app.exec();
}
//main.qml
import QtQuick 2.0
import CPP.Mycomponents 1.0
Rectangle {
width: 360
height: 360
Rectangle{
id:rect1
width:360
height:50
color:"transparent"
border.color: "black"
TextInput{
id:contextPropertyInput
anchors.left: parent.left
anchors.leftMargin: 5
width:350
height:50
color:"black"
font.pixelSize: 16
onTextChanged: employee.name = text
}
}
Rectangle{
width:360
height:50
color:"transparent"
border.color: "black"
anchors.top: rect1.bottom
anchors.topMargin: 10
TextInput{
id:customQMLTypeInput
anchors.left: parent.left
anchors.leftMargin: 5
width:360
height:50
color:"black"
font.pixelSize: 16
}
}
Employee{
id:qmlEmp;
name:customQMLTypeInput.text
}
}
See how the Employee is used as a QML type. You can also create a C++ object of Employee and set it as a context property using setContextProperty and edit that paritcular object. Choice is yours.