Hello and welcome to devnet,
yes it is possible to pass a string from Cpp to QML using a Model(It also works without a model), let me provide you an example:
main.cpp
#include "Model.h"
#include <QDeclarativeContext>
#include <QDeclarativeView>
#include <QApplication>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
QDeclarativeView *view = new QDeclarativeView;
QDeclarativeContext *context = view->rootContext();
QObject *object = (QObject *)view->rootObject();
Model *model = new Model(0);
view->setSource(QUrl("qrc:/qml/qmlview.qml"));
context->setContextProperty("listModel", model);
view->show();
return a.exec();
}
model.h
#ifndef MODEL_H
#define MODEL_H
#include <QModelIndex>
class Model : public QAbstractListModel
{
Q_OBJECT
public:
Model(QObject *parent);
~Model();
int rowCount(const QModelIndex &parent = QModelIndex()) const;
int columnCount(const QModelIndex &parent = QModelIndex()) const;
QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const;
enum Roles {
NameRole = Qt::UserRole
};
QHash<int, QByteArray> roleNames() const {
QHash<int ,QByteArray> roles;
roles[NameRole] = "name";
return roles;
}
};
#endif // MODEL_H
model.cpp
#include "Model.h"
Model::Model(QObject *parent)
:QAbstractListModel(parent)
{
}
int Model::rowCount(const QModelIndex &parent) const
{
return 4;
}
int Model::columnCount(const QModelIndex &parent) const
{
return 1;
}
QVariant Model::data(const QModelIndex &index, int role) const
{
if(role == NameRole)
{
return QString("Row%1, Column%2")
.arg(index.row() + 1)
.arg(index.column() +1);
}
return QVariant();
}
Model::~Model(){
}
src.qrc
<RCC>
<qresource prefix="/qml">
<file>qmlview.qml</file>
<file>image.bmp</file>
</qresource>
</RCC>
qmlview.qml
import QtQuick 1.1
Rectangle {
id: main
height: 200; width: 200
GridView {
id: view
width: 200; height: 200
model: listModel
delegate: Rectangle {
height: 25
width: 100
Text { text: name }
}
}
}
That way i pass 4 Strings to my QML file. The important part here is the data function, it returns the variable(QVariant) depending on the current index and role.
There is also an easier way to provide a string from Cpp to QML.
We will need an aditional setContextProperty in our main.cpp:
context->setContextProperty("myOwnCppText", QVariant("Yes it works"));
Let us just create a text in our QML-File:
Text {
width: 300; height: 20
text: myOwnCppText
}
It will display the text we pass from Cpp to QML. Another method would be to use the rootObject() and its setProperty() function. That way you just pass the name of the property as the first parameter and the value as the second one. Our QML-File should have included a property string variable, with the name of our first parameter:
property string anotherTextFromCpp: ""
Text {
width: 300; height: 20
text: anotherTextFromCpp
}
A third method would be to invoke a QML method from Cpp and pass the text as a string as a parameter. Then we can handle the text in our function however we want/need.
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