change text in QML textbox from C++ Qt 5.2.1 - c++

Question

I'm a little new to QML and C++ in general, but I'm learning quick. I'm a bit stumped on something though. I'm trying to make an application that reads text from a QML TextInput text field, and writes the data to a text area. I'm not sure what is going wrong, but upon reading the text I get the error "Unable to assign QQuickTextInput to QString" - and I'm a bit stumped on how to write back to a text area. If someone could shed some light, that would be appreciated. I've already been through the QML/C++ binding page, and that doesn't seem to help. I'm wondering if that page was written for an older version of Qt... Here's my code thus far:
QML:
import QtQuick 2.0
import QtMultimedia 5.0
import QtQuick.Controls 1.1
import QtQuick.Window 2.1
import QtWinExtras 1.0
import QtQuick.Layouts 1.1
Rectangle {
id: main
width: 640
height: 480
signal onClicked_button
TextInput {
id: textbocks
objectName: textbocks
x: 280
y: 230
width: 80
height: 20
text: "Text Input"
font.pixelSize: 12
Button {
id: button1
x: -10
y: 45
text: "Button"
onClicked:main.onClicked_button()
}
}
TextField {
id: textField1
x: 257
y: 329
placeholderText: qsTr("Text Field")
}
}
header (class - originally designed to write back to text input):
#ifndef TEST_H
#define TEST_H
#include <QObject>
#include <QtCore>
#include <QString>
#include <QQuickView>
#include <QQuickItem>
#include <QQmlComponent> // for accessing QML from C++
#include <QQmlContext> // for accessing C++ from QML
class test : public QObject
{
Q_OBJECT
public:
explicit test(QObject *parent = 0);
signals:
public slots:
void test_button(){
QQuickView *view = new QQuickView(QUrl("test.qml"));
view->show();
QQuickItem *item = view->rootObject();
QObject *item = object->findChild<QObject*>("textbocks");
textbox->setProperty("text", str);
delete textbox;
return;}
private:
bool switched;
bool textOutput;
QString str = "Hello World";
};
#endif // TEST_H
And main .cpp file:
#include "test.h"
#include <QGuiApplication>
#include <QtCore>
#include <QObject>
#include <QQuickItem>
#include <QQmlComponent>
#include <QQmlContext>
#include <QQuickView>
#include <QDeclarativeEngine>
#include <QDeclarativeComponent>
#include <QDeclarativeContext>
test::test(QObject *parent) :
QObject(parent)
{
}
int main (int argc, char*argv[]) {
QGuiApplication app(argc, argv);
QQuickView *view = new QQuickView(QUrl("test.qml"));
view->show();
QQuickItem *item = view->rootObject();
test *funcs = new test();
// connect button signals to their slots:
QObject::connect(item, SIGNAL(buttonClicked_button()), funcs, SLOT(test_button()));
delete funcs;
return 0;
}
Any help would be appreciated. Some of this is still a bit abstract for me... Thanks!!

Answer 1

as I noticed you are creating two QQuickViews from the same QML file "test.qml" :
1.In the main function (main.cpp)
2.and in the TEST_BUTTON function (test.h)
which are different QObject .
Another issues are that :
you are assigning an object of type TextInput to the objectName property (test.qml) which is a String
you are deleting (as Yekmen mentioned earlier) the object (textbox (test.h) = textbocks (test.qml)) which in the mean time you are assigning to it the string str="hello world" via setProperty() function .
Ahh forgot one, the slot name in C++ side which must be identical to the one declared in QML

Answer 2

I think you should look this method :
Connections {
target: area
onClicked: foo(parameters)
}
For example : area is your c++ object.( qmlRegisterType(myclass) )
area send a signal and after you can lauch your function.
I think is more easy.