Question

我正在尝试学习如何将Qt快速对象信号连接到c ++代码中的类中的插槽。当我将类定义添加到由系统创建的“qtquick2applicationviewer.h”文件时，一切正常。但我找不到添加我自己的.h文件的方法（我应该按照.h文件中的说明执行此操作：“建议不要修改此文件，因为较新版本的Qt Creator可能会提供更新版本的它。”）我尝试将源添加到.pro文件（HEADERS + = classes.h），也尝试将其添加到.pri文件（HEADERS + = $$ PWD /../ classes.h）但没有运气。

我得到的错误是链接器错误： LNK2001：未解析的外部sybol“public：virtual struct QMetaObject const * __thiscall MyClass :: metaObject（void）const”（？metaObject @ Myclass @@ UBEPBUQMetaObject @@ XZ）还有两个相似的。

对我做错的任何意见都非常感谢:) 可能可以帮助许多其他人，这也是基于QTQuick教程应用程序的一般性问题。

//classes.h
#ifndef CLASSES_H
#define CLASSES_H
#include <QObject>
#include <QVariant>
class MyClass : public QObject
{
    Q_OBJECT
public:
    MyClass(QObject *QMLObject) : m_QMLObject(QMLObject) {}

public slots:
    void handleClick() {
        m_QMLObject->setProperty("text", "Qt was here");
    }


protected:
    QObject *m_QMLObject;
};
#endif // CLASSES_H

//main.cpp
#include <QtGui/QGuiApplication>
#include "qtquick2applicationviewer.h"
#include "classes.h"
#include <QtQuick>
#include <QtDebug>

void MyClassInQtQhfile::cppSlot(const QString &msg) {
    qDebug() << "Called the C++ slot with message:" << msg;
}
int main(int argc, char *argv[])
{

    QTextStream out(stdout);

    QGuiApplication app(argc, argv);

    QtQuick2ApplicationViewer viewer;
    viewer.setMainQmlFile(QStringLiteral("qml/Transitions/main.qml"));
    viewer.showExpanded();
    QObject *rectangle = viewer.rootObject()->findChild<QObject*>("rectangle");
    QObject *text = viewer.rootObject()->findChild<QObject*>("text");
    MyClassInQtQhfile *myClassInQtQhfile = new MyClassInQtQhfile();
    MyClass *myclass = new MyClass(text);
    QObject::connect(rectangle, SIGNAL(qmlSignal(QString)),
                     myClassInQtQhfile, SLOT(cppSlot(QString)));
    QObject::connect(rectangle, SIGNAL(qmlSignal(QString)),
                     myclass, SLOT(handleClick()));
    //rectangle is the object name, which needs to be define in qml for the component.e.g. objectName: "rectangle"

    return app.exec();
}

//QML object sending signal
Rectangle {
                objectName: "rectangle"
                id: bottomLeftRect
                width: 64
                height: 64
                color: "#00000000"
                radius: 6
                anchors.left: parent.left
                anchors.leftMargin: 10
                anchors.bottom: parent.bottom
                anchors.bottomMargin: 20
                border.color: "#808080"
                signal qmlSignal(string msg)
                MouseArea {
                    id: mousearea3
                    anchors.fill: parent
                    onClicked:{
                        bottomLeftRect.qmlSignal("Hello from QML")
                        onClicked: page.state = 'State2'
                    }
                }
            }

qtquick2applicationviewer.pri的开头

# checksum 0x21c9 version 0x90005
# This file was generated by the Qt Quick 2 Application wizard of Qt Creator.
# The code below adds the QtQuick2ApplicationViewer to the project and handles
# the activation of QML debugging.
# It is recommended not to modify this file, since newer versions of Qt Creator
# may offer an updated version of it.

QT += qml quick

SOURCES += $$PWD/qtquick2applicationviewer.cpp
HEADERS += $$PWD/qtquick2applicationviewer.h
HEADERS += $$PWD/../classes.h
INCLUDEPATH += $$PWD
...

.pro文件

# Add more folders to ship with the application, here
folder_01.source = qml/Transitions
folder_01.target = qml
DEPLOYMENTFOLDERS = folder_01

# Additional import path used to resolve QML modules in Creator's code model
QML_IMPORT_PATH =

# The .cpp file which was generated for your project. Feel free to hack it.
SOURCES += main.cpp

# Installation path
# target.path =

# Please do not modify the following two lines. Required for deployment.
include(qtquick2applicationviewer/qtquick2applicationviewer.pri)
qtcAddDeployment()

HEADERS += \
    classes.h

QtQuick2找不到带有新类的.h文件

0 个答案: