myclass.h

#ifndef MYCLASS_H
#define MYCLASS_H

#include <QDebug>
#include <QObject>

class MyClass : public QObject
{
public:
    MyClass();

public slots:
    void buttonClicked();
    void buttonClicked(QString &in);
};

#endif // MYCLASS_H

myclass.cpp

#include "myclass.h"

MyClass::MyClass()
{
}

void MyClass::buttonClicked()
{
    // Do Something
}

void MyClass::buttonClicked(QString &in)
{
    qDebug() << in;
}

main.cpp中

#include <QApplication>
#include <QQmlApplicationEngine>
#include <myclass.h>
#include <QQmlContext>

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    QQmlApplicationEngine engine;
    engine.load(QUrl(QStringLiteral("qrc:///main.qml")));

    MyClass myClass;  // A class containing my functions

    // Trying to "SetContextProperty" as I saw people do it to achieve C++/QML connection
    QQmlContext * context = new QQmlContext(engine.rootContext());
    context->setContextProperty("_myClass", &myClass);

    return app.exec();
}

我想在myClass类中使用一个函数,它在单击QML按钮时接受QString参数.

当我编译&跑……一切顺利.
但是,当我单击按钮时…它在调试器中显示此错误：

qrc:///main.qml:80: ReferenceError: _myClass is not defined

〜&GT “我的QML文件中的第80行”：

74:    MouseArea {
75:        id: mouseArea1
76:        anchors.fill: parent
77:        hoverEnabled: true;
78:        onEntered: { rectangle1.border.width = 2 }
79:        onExited: { rectangle1.border.width = 1 }
80:        onClicked: _myClass.buttonClicked("Worked?")
81:    }

编辑:(至于导致编译错误的错误)

正如@Jairo所建议的那样,所有类都必须从QObject继承.

仍在寻找我的主要问题的解决方案.

解决方法:

哦,哦.这里有几个问题. (代码甚至编译？)

首先要做的事情.将某些内容传递给QML引擎的root属性时,无法创建新的上下文 – 您必须直接使用根上下文,如下所示：

engine.rootContext()->setContextProperty("_myClass", &myClass);

接下来,类定义存在一些问题.请参阅以下代码中的我的评论：

class MyClass : public QObject
{
    // This macro is required for QObject support.  You should get a compiler
    // error if you don't include this.
    Q_OBJECT

public:
    // QObjects are expected to support a parent/child hierarchy.  I've modified
    // the constructor to match the standard.
    explicit MyClass(QObject *parent = 0);

public slots:
    // This method needs to take either a QString or a const reference to one.
    // (QML doesn't support returning values via the parameter list.)
    void buttonClicked(const QString& in);
};

构造函数的实现应该将父项传递给基类：

MyClass::MyClass(QObject *parent) :
    QObject(parent)
{
}