How to write a QML extension from a custom C++ class?

gouneken

Good evening to the whole community, I am working on a mobile application project for search engine and for this I use the C++ and QML languages. I would like to extend my C++ class into a QML element. I tried to follow the procedure on the documentation, but at home it does not work as expected because when I implement my class in the main.qml file, I get the error message "Unknown component (M300)".
Here are some screenshots of my main.qml,

.pro

and .h

I am a beginner on Qt and I would like to know what my mistake is and how should I have done it. Thank you very much and I look forward to your answers.

gouneken

when I rerun, I am told that QtWebView cannot contain more than one item, so I guess I cannot save a c++ class in QtWebView, going through the doc I found that the c++ classes I needed had already been extended to the quick module. So, I'm going to use the c++ classes in this module instead. Thank you very much for your help.

dheerendra

Have you looked at this example in the documentation.

General steps...

Inherit class from OQObject
Register you class with qmlRegisterType(...)
import the package in qml(main.qml)

GrecKo

From a quick glance at your code it should work, have you tried running it and ignoring the Qt Creator warning?

gouneken

@dheerendra My class inherits from QWebEnginePage which inherits from QObject, so normally it also indirectly inherits from QObject

dheerendra

Show me where did you register you class ? I don't see an import statement at the top as well.

GrecKo

@dheerendra said in How to write a QML extension from a custom C++ class?:

Show me where did you register you class ? I don't see an import statement at the top as well.

The registration is done with QML_ELEMENT and

CONFIG += qmltypes
QML_IMPORT_NAME = QtWebView
QML_IMPORT_MAJOR_VERSION = 1

There's import QtWebView 1.0 at the top of the main.qml file

gouneken

when I rerun, I am told that QtWebView cannot contain more than one item, so I guess I cannot save a c++ class in QtWebView, going through the doc I found that the c++ classes I needed had already been extended to the quick module. So, I'm going to use the c++ classes in this module instead. Thank you very much for your help.