Not able to use QList<Class> ComponentA (solved)

p3c0

@alvinNew No need to hard code. You just need to store those values in an object of CComponent and add it to list. Define some setter methods in CComponent for storing values.

class CComponent{
    public:
    QString ComponentID;
    QString ComponentType;
    ...

    void setComponentId(QString id) {
    ComponentID = id;
    }

    void setComponentType(QString type) {
    ComponentType = type;
    }
};

//Then during appending

QList<CComponent> ComponentA;
while (xmlGet.findNextAndDescend("Component"))
{
      QString ComponentID = xmlGet.getAttributeString("ID","unknown");
      QString ComponentType = xmlGet.getAttributeString("Type","unknown");

       CComponent comp;
       comp.setComponentId(ComponentID); //store values
       comp.setComponentType(ComponentType); //store values

       //add that object to QList
       ComponentA.append(comp);
}

alvinNew

@p3c0

Many thanks, i can learn alot from your simple coding.

p3c0

@alvinNew You're Welcome :) Happy Coding ...
Also use ``` (3 backticks), key just above the tab button on keyboard for posting code blocks.

houmingc

My code is in pastebin, http://pastebin.com/JwKjfW0b
Like to ask how to read out the data in the class ( CComponent )

p3c0

@houmingc You will need to write getter methods as well which will return the values stored in those variables.

houmingc

Code below is not working although no compiler error

QList<CComponent> list;

   QListIterator<CComponent> i(list);
   while(i.hasNext()){
       qDebug()<<"xxxx is "<<ComponentTemplate.ComponentX;
   }

p3c0

@houmingc You are doing it wrong. First create some getter methods as said earlier. Then you need to cast the item to CComponent in the loop and access the getter methods to get the values stored in it.

p3c0

@houmingc Something like this

//CComponent class

void CComponent::setId(QString id)
{
    m_id = id;
}

QString CComponent::getId()
{
    return m_id;
}

QString m_id, m_type;

then to access after appending to list

QList<CComponent *> m_list;
...

CComponent *ca = new CComponent;
ca->setId("one");
ca->setType("big");
...

m_list.append(ca);

...

QListIterator<CComponent*> i(m_list);
while (i.hasNext()) {
    CComponent *comp = qobject_cast<CComponent*>(i.next()); //qobject_cast - if uses QObject
    qDebug() << comp->getId() << comp->getType();
}

houmingc

i have an error at cast object
error: no matching function for call to 'qobject_cast(CComponent* const&)'
CComponent comp = qobject_cast<CComponent>(i.next());

houmingc

qDebug() << ComponentList[0].GetComponentHeight(); // why accessing ComponentList array return error?

p3c0

@houmingc said:

i have an error at cast object
error: no matching function for call to 'qobject_cast(CComponent* const&)'
CComponent comp = qobject_cast<CComponent>(i.next());

Try it exactly how I have posted earlier in the example.

qDebug() << ComponentList[0].GetComponentHeight(); // why accessing ComponentList array return error?

What error ? ComponentList is a QList, right ?

houmingc

I got the each component display. Thanks.
No Casting needed.
How to get 3rd item of the class? i am now wondering if QList should be used instead of QLinkedList

   QLinkedList<CComponent>::iterator iterator;
    for(iterator=ComponentList.begin();iterator != ComponentList.end(); iterator ++)
    {
        qDebug()<<iterator->GetComponentAspectRatio()<<endl;
    }

p3c0

@houmingc Casting will be needed if you use QListIterator.

QList<CComponent*> m_list;

CComponent *ca = new CComponent;
ca->setId("one");
ca->setType("big");

m_list.append(ca);

QListIterator<CComponent*> i(m_list);
while (i.hasNext()) {
    CComponent *comp = qobject_cast<CComponent*>(i.next()); //qobject_cast - if uses QObject
    qDebug() << comp->getId() << comp->getType(); //access using QListIterator
}

/*-------------------------------------------------------------*/

qDebug() << m_list[0]->getType() << m_list[0]->getId(); //no need to cast