Problem with sending a message from C++ Class to QML

msauer75

Hi,

I want to send an error message from a slot to a message box in my QML view. In the class errorController I create a Q_PROPERTY

    Q_PROPERTY(QString ui_errMsg READ getErrMsg)

public:
    QString getErrMsg(void) {return errMsg;}

A private member of ErrorController is in my class masterController defined. So I defined a Q_PROPERTY in masterController

    Q_PROPERTY(gc::error::errorController* ui_errorController READ geterrorController CONSTANT)

public:
    gc::error::errorController* geterrorController() {return errorBox;}

The default content auf errMsg will be printed in the error box of my view

Item {
    Rectangle {
        anchors.fill: parent

        Image {
            width: parent.width
            height: parent.height
            source: Style.imageBackground
        }

        ErrorMessageBox {
            headerText: masterController.ui_errorController.ui_errMsg
        }
    }
}

If the content in errMsg changes during the execution of the programme the content of the error box won't be changed. Can you tell me where I do the mistake?

Thank you for your help.
BR
martin

SGaist

Hi,

You need to add a notification signal to your property to let the system know that something was changed.

Shrinidhi Upadhyaya

Hi @msauer75 , as @SGaist told,you need to add a notification signal telling that the value has changed.

For example:-

Q_PROPERTY(QString errMsg READ errMsg NOTIFY errMsgChanged)

and if you want WRITE property, i mean if you want to change the value from QML side then,

Q_PROPERTY(QString errMsg READ errMsg WRITE setErrMsg  NOTIFY errMsgChanged)

msauer75

Hi,

thank you for your help. It works.

BR
martin

Solved Problem with sending a message from C++ Class to QML