QML2与C++混合编程

最近有Qter找我问下关于QML和C++混合编程的问题，问我qmlc++是如何交互的，我总结了三点：

//1.第一种C++与QML交互的方法
//C++部分：
//这个方法在主类里面
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    NdooWebView ndooView(0);
    ndooView.resize(978,686);
    ndooView.show();
    int i= a.exec();
    ProjectManagerApi::getInstance()->stopRun();
    return i;
}
//这个方法在主类NdooWebView里面
void Widget::showMainQML()
{     
	    QDeclarativeView* noticeViewUi = new QDeclarativeView(0);
        noticeViewUi->setResizeMode(QDeclarativeView::SizeRootObjectToView);
        //noticeViewUi->setWindowModality(Qt::ApplicationModal);
        noticeViewUi->setWindowFlags(Qt::FramelessWindowHint|Qt::Dialog|Qt::WindowStaysOnTopHint);
        noticeViewUi->setAttribute(Qt::WA_TranslucentBackground);
        noticeViewUi->setStyleSheet("background:transparent;");
        noticeViewUi->setViewportUpdateMode(QGraphicsView::FullViewportUpdate);
        noticeViewUi->setSource(QUrl("qrc:/qml/main.qml"));
        QGraphicsObject* noticeViewObj = noticeViewUi->rootObject();
        connect(noticeViewObj,SIGNAL(signalMainMoveMent(int,QVariant)),this,SLOT(slotMovenoticeViewer(int,QVariant)));//signalMainMoveMent是qml里面的信号，slotMovenoticeViewer是本地的槽
		
		QMetaObject::invokeMethod(noticeViewUi->rootObject(),"ndooNoticeJsonString",
                              Q_ARG(QVariant,QVariant::fromValue(str)));//这个是C++可以把str值传到qml的ndooNoticeJsonString方法里面 str可以作为ndooNoticeJsonString的参数
}

//qml部分：
import QtQuick 1.1

Rectangle {
    id: name
    width: 280; height: 180
    signal signalMainMoveMent(int cmd,variant lst);//可以连接c++中的那个信号槽

    property variant lstData: []
    property int totalNum: 1
    property int currentNum: 1
    property int curPage: 1

	//这个控件触发一个信号到它的parent
    InoticeViewTopQml{
        id:top
        anchors.left: parent.left
        anchors.right: parent.right
        anchors.top: parent.top
        onSignalItemMoveMent: {
            signalMainMoveMent(cmd,lst);
        }
    }
    ListModel{
        id:notiModel
    }
	ListView{
	id:lstView
	}
	//就是C++里面的注册的方法
	function ndooNoticeJsonString(str)
	{
		var tmp = str;
		//做你想做的一些事情
	}
}

======================================================>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
//2.第2种C++与QML交互的方法
//C++部分
//定义一个接口类：datainterface
"datainterface.h"
class DataInterface : public QObject
{
    Q_OBJECT
    Q_PROPERTY(QString strError READ getError WRITE setError)
public:
    explicit DataInterface(QObject *parent = 0);
    QString getError(){ return strError;}
    void setError(const QString& error){strError = error;}
signals:
    void signalResponseDataReady(bool error,int cmd,QStringList finalData);
    void signalNotifyUI(bool error,int cmd,QStringList notifyData);
public slots:
    void slotRequestData(int cmd,QStringList parameterList);
    void slotResponseNotifyUI(bool error,int cmd,QStringList processResult);
    //qml notify widget to close

    //process widget singal
    void slotPcsamResponseDataReady(bool error,int cmd,QStringList finalData);
    void slotPcsamNotifyUI(bool error,int cmd,QStringList notifyData);
    void creatConnection();
    void slotdownloadOpenFile();
private:
    QString strError;
    bool isConnected;
};
"datainterface.cpp"
#endif // DATAINTERFACE_H
#include "datainterface.h"

DataInterface::DataInterface(QObject *parent) :
    QObject(parent),isConnected(false)
{
      creatConnection();
}

void DataInterface::slotRequestData(int cmd, QStringList parameterList)
{
//Widget为主类,以下类似
    Widget::instance()->requestData(cmd,parameterList);
    //PCSAM::instance()->slotRequestData(cmd);
}

void DataInterface::slotResponseNotifyUI(bool error, int cmd, QStringList processResult)
{
    Widget::instance()->responseNotifyUI(error,cmd,processResult);
}


//====================process pcsam signal======================================

void DataInterface::slotPcsamNotifyUI(bool error,int cmd, QStringList processResult)
{

     emit signalNotifyUI(error,cmd,processResult);
}

void DataInterface::slotPcsamResponseDataReady(bool error, int cmd, QStringList finalData)
{
    emit signalResponseDataReady(error,cmd,finalData);
}

//=======================creat connection in first request(connection depdent instance)==========================
void DataInterface::creatConnection()
{
      connect(Widget::instance(),SIGNAL(signalNotifyUI(bool,int,QStringList)),this,SLOT(slotPcsamNotifyUI(bool,int,QStringList)));
      connect(Widget::instance(),SIGNAL(signalResponseDataReady(bool,int,QStringList)),this,SLOT(slotPcsamResponseDataReady(bool,int,QStringList)));
}

//QML部分:
import MyDataPool 1.1//这个为main里面注册的接口类
import com.nokia.extras 1.1
//*
Item{
//cmd为信号的第一个参数指代哪个命令
DataPool{
        id:dataPool
        onSignalNotifyUI:{
            if(!error){                
                switch(cmd){
                case WIFI_GET_MODEL:{
                    console.log("--------ddddd----"+ notifyData);
                    if(notifyData[1]=="unknown")
                    {
                        dlg.currentDevice = "Android Device"
                        return;
                    }
                    dlg.currentDevice = notifyData[1]
                }break;
				}
			}
		}
		onSignalResponseDataReady: {
            switch(cmd)
            {
            case TRADE_MS_REQUEST_MAINUI:
            {
                //cmd为信号的第一个参数指代哪个命令
                if(finalData[0] == "1")
                {
                   //connectingTips
                }
                else if(finalData[0] == "2")
                {
                }
            }break;
            }
        }
		}
}
#include "dataInterface.h"
#include <QtDeclarative>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
	qmlRegisterType<DataInterface>("MyDataPool",1,1,"DataPool");//main注册接口类
    int i= a.exec();
    ProjectManagerApi::getInstance()->stopRun();
    return i;
}

//具体使用情况多参考QML与C++交互文档

细看见文档:QML与C++交互实例

另外添加以下官方的说明QML2 C++