Qt工作笔记-第一个QML（QQuickView显示QML文件）

程序运行截图如下：

程序结构如下：

代码如下：

main.cpp

#include <QApplication>
#include <QDir>
#include <QQuickView>
#include <QUrl>
#include <QQmlEngine>

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

    QQuickView viewer;
    viewer.setSource(QUrl("qrc:/main.qml"));
    viewer.setResizeMode(QQuickView::SizeRootObjectToView); //默认的，不写也阔以
    viewer.show();

    return a.exec();
}

main.qml

import QtQuick 2.0


Item {
    width:800;  //这个;可以有，也可以没有，不敲;我心理面不舒服
    height:600;

    QtObject{
        id:myObject;
        property int counter;
        Component.onCompleted: {
            myObject.counter=100;
        }
    }


    Rectangle{
        id:topInformation;
        anchors.top: parent;
        width:parent.width;
        height:80;
        opacity:0.6
        color:"black";
        Text{
            id:myTopText;
            color:"white";
            anchors.centerIn: parent;
            text:"这是一个显示消息长方体，透明度为0.6！";
            font.pixelSize: 22;
        }
        MouseArea{
            anchors.fill: parent;
            onPressed:{
                myTopText.text="现在：鼠标左键按下了！点击的是矩形框！";
            }
            onReleased: {
                myTopText.text="现在：鼠标左键释放了！点击的是矩形框！";
            }
        }
    }

    Rectangle{
        id:centerInformation;
        anchors.centerIn: parent;
        width:parent.width;
        height:80;
        opacity:0.7
        color:"gray";
        Text{
            id:myCenterText;
            color:"white";
            anchors.centerIn: parent;
            font.pixelSize: 22;
            text:myObject.counter;
        }
        MouseArea{
            anchors.fill: parent;
            onClicked: {
                countDown.start();
            }
        }

    }

    Timer{
        id:countDown;
        interval:20;
        repeat:true;
        triggeredOnStart: true;
        onTriggered: {
            myCenterText.text=myObject.counter;
            myObject.counter-=1;
            if(myObject.counter<0){
                countDown.stop();
                myCenterText.text="已经为0了！";
            }
        }
    }

}