How QML emit signal,C++ receive signal from QML ,,,

bonbinker

such as
int the *.qml
@signal musicSeek(int x);
MouseArea{
//onPositionChanged: slider.x=mouse.x
anchors.fill:parent
drag.target: parent
drag.minimumX: 2 ;drag.maximumX:400
onClicked: {
slider.x=mouse.x-32
musicSeek(slider.x)
}
}@

in the main.cpp
@QObject rootObject=dynamic_cast<QObject>(view.rootObject());
connect(rootObject,SIGNAL(musicSeek(int)),this,SLOT(lseek(int)));
@
but is debug,,the result is Object::connect: No such signal QDeclarativeRectangle::musicSeek(int) in ..\3Dqml\main.cpp
it is dont't find signal...

who know ,,please tell me ..God bless me

[Edit: Please, don't forget @-tags /Vass]

sigrid

The following "wiki page":http://developer.qt.nokia.com/wiki/Connect_a_complex_signal_from_QML_to_Qt contains an example that shows how to connect a signal from QML to C++. Does it help solve your problem?

bonbinker

[quote author="sigrid" date="1316422549"]The following "wiki page":http://developer.qt.nokia.com/wiki/Connect_a_complex_signal_from_QML_to_Qt contains an example that shows how to connect a signal from QML to C++. Does it help solve your problem?
[/quote]thank you ,,the is single case ,,your case use QDEclarativeItem..
QDeclarativeItem *item = qobject_cast<QDeclarativeItem *>(view.rootObject());

my code is QObject rootObject=dynamic_cast<QObject>(view.rootObject());
my class from QOBject inherit..
in the Object::connect: No such signal QDeclarativeRectangle::musicSeek(int)
QDeclarativeRectangle maybe is promblem key...

thank you ....

sigrid

It is hard to tell what's causing this problem without more information. Can you post a small, complete example that reproduces the issue you are having?

bonbinker

thank you ,,I give up signal and slot connect modle...
use
@
Q_INVOKABLE void lseek(qint64 temp);

MouseArea{
****
onReleased:Main.seekChanged();
}

function seekChanged(){
var m=(slider.x)/hex*1000
//console.log("the current m:")
//console.log(m)
music.lseek(m)
}
@
this modle may run, then my brain is orderless
haha ,,
thank you very much.....

[Edit: Code formatting. Please use @ tags; mlong]

TreNrod

Hi,

had a similar problem. Searched for the easiest approach.

No declariation inthe main.qml: signal insertNewItem(string dayId, string amount, string descr, string group)
No signal and slots connection: QObject::connect(item, SIGNAL(insertNewItem(...

This is how it works in my example:

The Button where the signal is triggered
@
Button {
id:but_Add
height: 50
width: parent.width
text: "Add"

        MouseArea{
            anchors.fill: parent
            onClicked: {
                //C++ class containing the slot
                dataHandler.insertNewItem(dateKey, txtInAmount.text, txtInReason.text, txtInGroup.text)
            }
            onPressed: {
                parent.color = "blue"

            }
            onReleased: {
                parent.color = "white"
            }
        }
    }

@

Just a slots declination in the DateHandler...
@
public slots:
void insertNewItem(const QString &dayId, const QString &amount, const QString &descr, const QString &group);
@

.. which we send give the context Property as a "dateHandler" to use in QML
@
m_dataHandler = new DataHandler(this);
m_context->setContextProperty("dataHandler", m_dataHandler);
@
Best regards

luca

You could try to remove ';' character in:
@
signal musicSeek(int x);
@