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1 QML获取C的变量值
2 QML获取C创建的自定义对象
3 QML发送信号绑定C端的槽
4 C端发送信号绑定qml端槽
5 C调用QML端函数 1 QML获取C的变量值
QQmlApplicationEngine engine;
全局对象
上下文属性
QQmlApplicationEngine engine;
QQmlContext *context1 engine.…目录
1 QML获取C的变量值
2 QML获取C创建的自定义对象
3 QML发送信号绑定C端的槽
4 C端发送信号绑定qml端槽
5 C调用QML端函数 1 QML获取C的变量值
QQmlApplicationEngine engine;
全局对象
上下文属性
QQmlApplicationEngine engine;
QQmlContext *context1 engine.rootContext();
context1-setContextProperty(test,200);
在qml中可全局直接使用test
2 QML获取C创建的自定义对象
光标放在成员变量m_iValue和m_sString后面 Alt Enter 选择第一个可自动生成函数
int m_iValue; QString m_sString;
myobject.h
#ifndef MYOBJECT_H
#define MYOBJECT_H#include QObjectclass MyObject : public QObject
{Q_OBJECT
public:explicit MyObject(QObject *parent nullptr);int iValue() const;void setIValue(int newIValue);const QString sString() const;void setSString(const QString newSString);signals:void iValueChanged();void sStringChanged();private:int m_iValue;QString m_sString;Q_PROPERTY(int iValue READ iValue WRITE setIValue NOTIFY iValueChanged)Q_PROPERTY(QString sString READ sString WRITE setSString NOTIFY sStringChanged)
};#endif // MYOBJECT_Hmyobject.c
#include myobject.hMyObject::MyObject(QObject *parent): QObject{parent}
{}int MyObject::iValue() const
{return m_iValue;
}void MyObject::setIValue(int newIValue)
{if (m_iValue newIValue)return;m_iValue newIValue;emit iValueChanged();
}const QString MyObject::sString() const
{return m_sString;
}void MyObject::setSString(const QString newSString)
{if (m_sString newSString)return;m_sString newSString;emit sStringChanged();
}mian.c
注册main.qml 中 import testObj 1.0使用
qmlRegisterTypeMyObject(testObj,1,0,MyObject);
main.qml
import QtQuick 2.15
import QtQuick.Window 2.15
import QtQuick.Controls 2.5
import testObj 1.0
Window {width: 640height: 480visible: truetitle: qsTr(Hello World)MyObject {iValue: 20sString: test}}
使用c端的函数时需要在函数前面加上 Q_INVOKABLE
比如 Q_INVOKABLE void myFunction();
3 QML发送信号绑定C端的槽
在mian.c先注册 qmlRegisterTypeMyObject(testObj,1,0,MyObject);
C 写一个公有槽
public slots: void qml_slot(QString str);
qml端通过按钮发送信号
signal qml_signal(string str) Button { onClicked: { qml_signal(qml send signal test); } }
绑定信号和槽函数
Component.onCompleted: { qml_signal.connect(myobj.qml_slot) }
import QtQuick 2.15
import QtQuick.Window 2.15
import QtQuick.Controls 2.5
import testObj 1.0
Window {id: windowwidth: 640height: 480visible: truetitle: qsTr(Hello World)MyObject {id: myobjiValue: 20sString: test}signal qml_signal(string str)Button {onClicked: {qml_signal(qml send signal test);}}//方法一
// Connections {
// target: window
// function onQml_signal(str){
// myobj.qml_slot(str)
// }
// }//方法二Component.onCompleted: {qml_signal.connect(myobj.qml_slot)}//方法三 mian.c 中engine load后//auto obj_list engine.rootObjects();//auto window list.first();//connect(window,SIGNAL(qml_signal(QString)),your function ptr,SLOT(qml_slot(QString)));}
4 C端发送信号绑定qml端槽
myobject.h
信号 void signal_Cpp(QString str); 通过函数
Q_INVOKABLE void myFunction();发送
#ifndef MYOBJECT_H
#define MYOBJECT_H#include QObjectclass MyObject : public QObject
{Q_OBJECT
public:explicit MyObject(QObject *parent nullptr);int iValue() const;void setIValue(int newIValue);const QString sString() const;void setSString(const QString newSString);Q_INVOKABLE void myFunction();static MyObject* getInstance();
public slots:void qml_slot(QString str);
signals:void iValueChanged();void sStringChanged();void signal_Cpp(QString str);
private:int m_iValue;QString m_sString;Q_PROPERTY(int iValue READ iValue WRITE setIValue NOTIFY iValueChanged)Q_PROPERTY(QString sString READ sString WRITE setSString NOTIFY sStringChanged)
};#endif // MYOBJECT_Hmyobject.c
#include myobject.h
#include QDebug
MyObject::MyObject(QObject *parent): QObject{parent}
{}int MyObject::iValue() const
{return m_iValue;
}void MyObject::setIValue(int newIValue)
{if (m_iValue newIValue)return;m_iValue newIValue;emit iValueChanged();
}const QString MyObject::sString() const
{return m_sString;
}void MyObject::setSString(const QString newSString)
{if (m_sString newSString)return;m_sString newSString;emit sStringChanged();
}void MyObject::myFunction()
{emit signal_Cpp(signal_Cpp myFunction!);
}MyObject *MyObject::getInstance()
{static MyObject* obj new MyObject();return obj;
}void MyObject::qml_slot(QString str)
{qDebug()qml_slotstr;
}mian.c
注册单例类
qmlRegisterSingletonInstance(testObj,1,0,MyObject,MyObject::getInstance());
#include QGuiApplication
#include QQmlApplicationEngine
#include QQmlContext
#include QtQml/qqml.h
#include myobject.hint main(int argc, char *argv[])
{
#if QT_VERSION QT_VERSION_CHECK(6, 0, 0)QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
#endifQGuiApplication app(argc, argv);QQmlApplicationEngine engine;QQmlContext *context1 engine.rootContext();context1-setContextProperty(test,200);//qmlRegisterTypeMyObject(testObj,1,0,MyObject);qmlRegisterSingletonInstance(testObj,1,0,MyObject,MyObject::getInstance());const QUrl url(QStringLiteral(qrc:/main.qml));QObject::connect(engine, QQmlApplicationEngine::objectCreated,app, [url](QObject *obj, const QUrl objUrl) {if (!obj url objUrl)QCoreApplication::exit(-1);}, Qt::QueuedConnection);engine.load(url);return app.exec();
}main.qml
C端发送信号
Button { onClicked: { //C发送信号 MyObject.myFunction() } }
连接QML端槽函数
Connections { target: MyObject function onSignal_Cpp(str) { //qml槽函数 qmlSolt(str) } }
import QtQuick 2.15
import QtQuick.Window 2.15
import QtQuick.Controls 2.5
import testObj 1.0
Window {id: windowwidth: 640height: 480visible: truetitle: qsTr(Hello World)// MyObject {
// id: myobj
// iValue: 20
// sString: test// }function qmlSolt(str) {console.log(str)}signal qml_signal(string str)Button {onClicked: {//C发送信号MyObject.myFunction()}}Connections {target: MyObjectfunction onSignal_Cpp(str) {//qml槽函数qmlSolt(str)}}}5 C调用QML端函数
//main.c load后获取qml对象 auto obj_list engine.rootObjects(); auto window obj_list.first(); //调用QML函数 QMetaObject::invokeMethod(window,qmlFunction, Q_RETURN_ARG(QVariant,res), Q_ARG(QVariant,arg1), Q_ARG(QVariant,arg2) );
mian.qml
import QtQuick 2.15
import QtQuick.Window 2.15
import QtQuick.Controls 2.5
import testObj 1.0
Window {id: windowwidth: 640height: 480visible: truetitle: qsTr(Hello World)function qmlFunction(arg1,arg2) {return arg1 arg2;}}
mian.c
#include QGuiApplication
#include QQmlApplicationEngine
#include QQmlContext
#include QtQml/qqml.h
#include myobject.hint main(int argc, char *argv[])
{
#if QT_VERSION QT_VERSION_CHECK(6, 0, 0)QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
#endifQGuiApplication app(argc, argv);QQmlApplicationEngine engine;QQmlContext *context1 engine.rootContext();context1-setContextProperty(test,200);qmlRegisterTypeMyObject(testObj,1,0,MyObject);//qmlRegisterSingletonInstance(testObj,1,0,MyObject,MyObject::getInstance());const QUrl url(QStringLiteral(qrc:/main.qml));QObject::connect(engine, QQmlApplicationEngine::objectCreated,app, [url](QObject *obj, const QUrl objUrl) {if (!obj url objUrl)QCoreApplication::exit(-1);}, Qt::QueuedConnection);engine.load(url);//获取qml对象auto obj_list engine.rootObjects();auto window obj_list.first();QVariant res;QVariant arg1 arg1;QVariant arg2 arg2;//调用QML函数QMetaObject::invokeMethod(window,qmlFunction,Q_RETURN_ARG(QVariant,res),Q_ARG(QVariant,arg1),Q_ARG(QVariant,arg2));qDebug()res;return app.exec();
}
