qml定时器示例

效果是红色图形每隔一秒移动一次，循环在窗口绕圈圈

头文件，qml文件要加入到资源文件哦

#ifndef WIDGET_H

#define WIDGET_H

#include <QWidget>

#include <QQuickWidget>

#include <QQmlContext>

class Widget : public QWidget

{

    Q_OBJECT 

    //使得qml可以引用widget的属性，大概的意思是窗口大小改变发出RectChanged信号，然后返回改变后的大小width和height赋值给_width,_height

    Q_PROPERTY(int _width READ returnW NOTIFY RectChanged)

    Q_PROPERTY(int _height READ retrunH NOTIFY RectChanged)

public:

    Widget(QWidget *parent = 0);

    ~Widget();

    int returnW(){return _width = width();}

    int retrunH(){return _height = height();}

    void resizeEvent(QResizeEvent *event);

signals:

    void RectChanged();

private:

    QQuickWidget *qmlWidget;

    int _width, _height;

};

#endif // WIDGET_H

源文件

#include "widget.h"

Widget::Widget(QWidget *parent)

    : QWidget(parent)

{

    qmlWidget = new QQuickWidget(this);

    qmlWidget->rootContext()->setContextProperty("View",this);

    qmlWidget->setSource(QUrl(QStringLiteral("qrc:/Timer.qml")));

    resize(700,500);

}

Widget::~Widget()

{

    if(qmlWidget)

    {

        delete qmlWidget;

        qmlWidget = NULL;

    }

}

void Widget::resizeEvent(QResizeEvent *event)

{

    emit RectChanged();

}

qml文件

import QtQuick 2.0

import QtQuick.Controls 1.4

Rectangle {

    id: root

    width: View._width

    height: View._height

    color: "green"

    Rectangle {

        id: rect

        x: 0; y: 0

        width: 50

        height: 50

        color: "red"

    }

    property var walk: false

    Timer {

        id: timer

        interval: 1000

//这个属性设置为true才能每隔1秒触发一次onTriggered.

        repeat: true

        onTriggered: {

            if(rect.x+50 < root.width && !walk)

            {

                rect.x += 50;

            }else

            {

                if(rect.y+50<root.height && !walk)

                {

                    rect.y += 50;

                }else

                {

                    walk = true;

                    if(rect.x-50>0)

                    {

                        rect.x -= 50;

                    }else

                    {

                        if(rect.y-50>0)

                        {

                            rect.y -= 50;

                        }else

                        {

                            walk = false;

                        }

                    }

                }

            }

        }

    }

    Button {

        anchors.centerIn: parent

        onClicked: timer.start()

        text: "Start"

    }

}