1、在与qml通信的时候，需要把函数接口暴露给qml需要在函数前面加入Q_INVOKABLE关键字，且需要注意成员函数的公有或私有类型。

例如：

.h文件

 

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();
    Q_INVOKABLE QString sendData();

private:
    Ui::MainWindow *ui;
};

#endif // MAINWINDOW_H

 

.cpp文件

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QQuickItem>
#include <QQmlApplicationEngine>
#include <QQuickView>
#include <QQmlContext>

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    QUrl soucre("qrc:/qml/text.qml");
    ui->quickWidget->setResizeMode(QQuickWidget::SizeRootObjectToView);
    ui->quickWidget->rootContext()->setContextProperty("testData", this);
    ui->quickWidget->setSource(soucre);
    ui->quickWidget->setClearColor(QColor(Qt::transparent));
}

MainWindow::~MainWindow()
{
    delete ui;
}

QString MainWindow::sendData()
{
    QString str = "blue";
    return str;
}

main.cpp

#include "mainwindow.h"
#include <QApplication>
#include <QQmlApplicationEngine>
#include <QQmlContext>
#include <QQuickView>

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

    MainWindow w;
    w.show();

    return a.exec();
}

text.qml

import QtQuick 2.0
import QtQuick.Controls 1.4
Rectangle{
    id:root;
    height:200;
    width:200;
    color: "red"
    Text {
        anchors.centerIn: parent
        text: qsTr("hello")
    }
    MouseArea{
        anchors.fill: parent;
        onClicked: {
            root.color = testData.sendData()
        }
    }
}