Strange problem with a method in Qt

Adrian.Aioanei

Hey all :D

I have a strange problem. I have created a QML interface (the interface is the default interface with tow buttons in footer) and in QML i have created same Labels and i populate them with same string from C++.
Here is what i am doing in main function.

int main(int argc, char *argv[])
{
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
    QGuiApplication app(argc, argv);
    AnimalModel model;
    model.addAnimal(Animal("1", "2"));
    model.addAnimal(Animal("1", ""));
    model.addAnimal(Animal("1", "2"));
    model.addAnimal(Animal("1", "2"));
    QQuickView view;
    view.setResizeMode(QQuickView::SizeRootObjectToView);
    QQmlContext *ctxt = view.rootContext();
    ctxt->setContextProperty("myModel", &model);
    view.setSource(QUrl("qrc:/main.qml"));

When i do this in main evreathing works ok, but if i make an other class and i make a method like this:

 void AddData::insertDataToLabels()
{
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
    QGuiApplication app(argc, argv);
    AnimalModel model;
    model.addAnimal(Animal("1", "2"));
    model.addAnimal(Animal("1", ""));
    model.addAnimal(Animal("1", "2"));
    model.addAnimal(Animal("1", "2"));
    QQuickView view;
    view.setResizeMode(QQuickView::SizeRootObjectToView);
    QQmlContext *ctxt = view.rootContext();
    ctxt->setContextProperty("myModel", &model);
    view.setSource(QUrl("qrc:/main.qml"));

And after that i call that method in main like this:

int main(int argc, char *argv[])
{
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
    QGuiApplication app(argc, argv);
    AppData data;
    data.insertDataToLabels();
    return app.exec();
}

Works but the default buttons from the footer doesn't work anymore.
If i use the objects directly in main like above works ok, if i make a class with method and put the code from main buttons doesn't work anymore.
Is there a reason why my the buttons doesn't work if i call that method? The labels are also populated and i don't have any error or wornings.
thank you :)

? Offline

Hi!

 void AddData::insertDataToLabels()
{
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
    QGuiApplication app(argc, argv);
    AnimalModel model;

Here, model is local to insertDataToLabels(). Once this functions returns, model becomes invalid. As your context property points to an invalid object after this, the behavior of your program becomes undefined.

Adrian.Aioanei

Ohh yes..how stupid I am.
The problem is with insert data. I dont't have any other choice. I need a class that write have a method that write data.
Do you have any idea about how can i solve this @Wieland ?
Thank you for your replay.

? Offline

Maybe something like this:

class AppData
{
public:
    void insertDataToLabels()
    {
        m_model.addAnimal(Animal("1", "2"));
        // ...
    }
private:
    AnimalModel m_model;
};

Adrian.Aioanei

I have try but also i have the model header included in my AppData i receive this erors:

D:\Qt_prog\textQtInterface\model.h:6: error: C2011: 'Animal': 'class' type redefinition
D:\Qt_prog\textQtInterface\model.h:20: error: C2011: 'AnimalModel': 'class' type redefinition
D:\Qt_prog\textQtInterface\adddata.h:11: error: C2079: 'AddData::m_model' uses undefined class 'AnimalModel'

The AppData looks like this:

#ifndef ADDDATA_H
#define ADDDATA_H

#include"model.h"

class AddData
{
public:
     void insertDataToLabels();
private:
     AnimalModel m_model;
};

#endif // ADDDATA_H

Adrian.Aioanei

I have solved the above problem (i have double included a header).
Also with this things set the interface also in stock.

So the problem is the same.
If i do something like this in main:

int main(int argc, char *argv[])
{
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
    QGuiApplication app(argc, argv);
    qmlRegisterType<TerminalLauncher>("com.example.launcher", 1, 0, "Launcher");
    AppData data;
   data.insertDataToLabels();
    return app.exec();
}
``
The buttons freeze, but if i put all the code for "model" object in main works ok.`

SGaist

Hi,

Why are you creating another application in insertDataToLabels ?