我正在使用C ++和QML在QT中编写应用程序来复制车辆上的仪表。我的目标是每次在鼠标区域中单击鼠标时调用c ++函数。我用Google搜索并尝试了很多东西，但是仍然无法在鼠标点击时调用我的C ++函数。由于我是QT的新手，我不知道我做错了什么。请帮忙解决这个问题。
Gauge.pro文件：
folder_01.SOURCES = qml/testlib
folder_01.TARGET = qml
DEPLOYMENTFOLDERS = folder_01
TEMPLATE = app
QT += qml quick
CONFIG += c++11
CONFIG += static
SOURCES += main.cpp \
rotationThread.cpp
RESOURCES += qml.qrc
# Additional import path used to resolve QML modules in Qt Creator's code model
QML_IMPORT_PATH =
# Default rules for deployment.
include(deployment.pri)
QT += declarative
HEADERS += \
rotationThread.h
rotationThread.h文件
#ifndef ROTATIONTHREAD_H
#define ROTATIONTHREAD_H
#include <QThread>
#include <QObject>
class rotationThread : public QThread, public QObject
{
private:
QObject *rootObject, *leftNeedleObj, *rightGaugeObj, *unacHeadObj, *mouseAreaObj;
Q_OBJECT
protected:
Q_INVOKABLE void run();
public:
rotationThread(QObject *pobj);
};
#endif // ROTATIONTHREAD_H
Main.cpp的
#include <QGuiApplication>
#include <QApplication>
#include <QDeclarativeView>
#include <QDeclarativeContext>
#include <QQmlApplicationEngine>
#include <QtCore>
#include <QtGui>
#include <QtNetwork>
#include <QDebug>
#include <QPropertyAnimation>
#include <QDebug>
#include <QVariantAnimation>
#include <windows.h>
#include <QThread>
#include <rotationThread.h>
#include <QGraphicsObject>
#include <QQmlApplicationEngine>
#include <QtQml>
int main(int argc, char *argv[])
{
QGuiApplication app(argc, argv);
QQmlApplicationEngine engine;
engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
//Get access to the root objects
QObject *rootObject = (QObject *)engine.rootObjects().front();
//QObject *mouseAreaObj = rootObject->findChild<QObject *>("mouseArea");
rotationThread rot(rootObject);
qmlRegisterType<rotationThread(rot)>("testlib", 1, 0, "rotationThread");
//QEvent *event;
//QMouseEvent *event;
// QObject::connect(mouseAreaObj, SIGNAL(clicked), qGuiApp, SLOT(rot.start()));
/*if(event->type() == QEvent::MouseButtonPress)
{
rot.start();
}*/
return app.exec();
}
rotationThread.cpp
#include "rotationThread.h"
#include <QVariant>
#include <QtMath>
#include <QCursor>
#include <QMouseEvent>
rotationThread::rotationThread(QObject *pobj)
{
rootObject = pobj;
}
void rotationThread::run()
{
leftNeedleObj = rootObject->findChild<QObject *>("leftNeedle");
rightGaugeObj = rootObject->findChild<QObject *>("rightGauge");
unacHeadObj = rootObject->findChild<QObject *>("unacHead");
mouseAreaObj = rootObject->findChild<QObject *>("mouseArea");
QVariant angle=0, dummyX=0, dummyY=0;
qreal x=0, y=0, div=0, calcAng=0;
QPoint pos;
dummyX = mouseAreaObj->property("x");
dummyY = mouseAreaObj->property("y");
x = dummyX.toReal();
y = dummyY.toReal();
/*QMouseEvent *clicked;
if(clicked->button() == Qt::LeftButton)
{*/
//pos = QCursor::pos();
//x = pos.x();
//y = pos.y();
div = (y/x);
//At Origin
if((x==0) && (y==0) )
{
angle = 0;
}
//At first quadrant
if((x>0) && (y>0) )
{
calcAng = qAtan(div);
angle = calcAng;
}
//At second quadrant
if((x<0) && (y>0) )
{
calcAng = qAtan(div);
calcAng = -(90 + calcAng);
angle = calcAng;
}
//At third quadrant
if((x<0) && (y<0) )
{
calcAng = qAtan(div);
calcAng = -(calcAng - 90);
angle = calcAng;
}
//At fourth quadrant
if((x>0) && (y<0) )
{
calcAng = qAtan(div);
calcAng = -(calcAng - 90);
angle = calcAng;
}
QThread::msleep(100);
leftNeedleObj->setProperty("stepRot", angle);
rightGaugeObj->setProperty("stepRot", angle);
unacHeadObj->setProperty("stepRot", angle);
/*//Rotating Clockwise
while(angle<=360)
{
QThread::msleep(100);
leftNeedleObj->setProperty("stepRot", angle);
rightGaugeObj->setProperty("stepRot", angle);
unacHeadObj->setProperty("stepRot", angle);
angle = angle.toInt() + 5;
}*/
QThread::msleep(100);
angle=0;
//}
//Rotating Anticlockwise
/*angle=0;
while(angle>=(-360))
{
QThread::msleep(100);
leftNeedleObj->setProperty("stepRot", angle);
rightGaugeObj->setProperty("stepRot", angle);
unacHeadObj->setProperty("stepRot", angle);
angle = angle.toInt() - 5;
}
angle=0;*/
}
main.qml
import QtQuick 2.3
import QtQuick.Window 2.2
import testlib 1.0
Window {
id: mainWindow
objectName: "mainWindow"
width: 800
height: 800
color: "#000000"
visible: true
rotationThread{
id: thread
objectName: "thread"
}
Rectangle {
id: gaugeRec
objectName: "gaugeRec"
x: 0
y: 0
width: 800
height: 361
color: "#000000"
gradient: Gradient {
GradientStop {
position: 0
color: "#000000"
}
GradientStop {
position: 1
color: "#000000"
}
}
Image {
id: leftGauge
objectName: "leftGauge"
x: 32
y: 29
width: 290
height: 290
source: "leftGauge.png"
Image {
id: leftNeedle
objectName: "leftNeedle"
property real stepRot: 0
rotation: 0
x: 100
y: 100
width: 90
height: 90
source: "leftNeedle.png"
transform:
Rotation { origin.x: 45; origin.y: 45; angle: leftNeedle.stepRot}
smooth: true
}
}
Image {
id: rightGauge
objectName: "rightGauge"
property real stepRot: 0
x: 471
y: 31
width: 290
height: 290
source: "rightGauge.png"
transform:
Rotation { origin.x: 145; origin.y: 145; angle: rightGauge.stepRot }
smooth: true
}
Image {
id: rightNeedle
objectName: "rightNeedle"
x: 571
y: 131
width: 90
height: 90
source: "rightNeedle.png"
}
}
Rectangle {
id: headRec
objectName: "headRec"
x: 48
y: 386
width: 709
height: 394
color: "#000000"
gradient: Gradient {
GradientStop {
position: 0
color: "#000000"
}
GradientStop {
position: 1
color: "#000000"
}
}
Image {
id: railTrack
objectName: "railTrack"
x: 279
y: 100
width: 154
height: 294
source: "railTrack.png"
Image {
id: unacHead
objectName: "unacHead"
property real stepRot: 0
x: 63
y: -165
width: 26
height: 328
visible: true
source: "unacHead.png"
transform:
Rotation { origin.x: 13; origin.y: 164; angle: unacHead.stepRot }
smooth: true
}
}
}
MouseArea {
id: mouseArea
objectName: "mouseArea"
x : 0
y : 0
width: 800
height: 800
hoverEnabled: false
visible: true
acceptedButtons: Qt.LeftButton | Qt.RightButton
onClicked: { thread.run(); }
}
}
答案 0 :(得分：0)
我不知道你对你的课程究竟想要什么（QThread，QObject ......），但是试试这个从qml调用c ++函数。
<强> myobject.cpp
#include "myobject.h"
#include <QDebug>
MyObject::MyObject(QObject *parent) : QObject(parent)
{
}
void MyObject::myFunction(double mouseX, double mouseY)
{
qDebug() << "My cpp function" << mouseX << mouseY;
}
<强> myobject.h
#ifndef MYOBJECT_H
#define MYOBJECT_H
#include <QObject>
class MyObject : public QObject
{
Q_OBJECT
public:
explicit MyObject(QObject *parent = 0);
Q_INVOKABLE void myFunction(double mouseX, double mouseY);
signals:
public slots:
};
#endif // MYOBJECT_H
<强>的main.cpp
#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QQmlContext>
#include "myobject.h"
int main(int argc, char *argv[])
{
QGuiApplication app(argc, argv);
QQmlApplicationEngine engine;
engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
MyObject myObject;
engine.rootContext()->setContextProperty("myObject", &myObject);
return app.exec();
}
main.qml
import QtQuick 2.3
import QtQuick.Window 2.2
import QtQuick.Controls 1.2
Window {
id: mainWindow
width: 100
height: 100
visible: true
MouseArea {
id: mouseArea
anchors.fill: parent
onClicked: {
myObject.myFunction(mouseArea.mouseX, mouseArea.mouseY);
}
}
}
希望这能帮到你！