QtQuick(QML)自学之路（5）自定义信号

参考书籍《Qt quick 核心编程》
书籍作者 https://blog.csdn.net/foruok/article/details/30028711

顺便说下 信号也可以连接信号

import QtQuick 2.14
import QtQuick.Window 2.14
import QtQuick.Controls 2.14
Window {
    
    
    id:root;
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World");

    Rectangle {
    
    
        id:rec;
        width:100;
        height:100;
        anchors.centerIn: parent;
        property int num:0;//定义了一个变量num
        color: "black";
        Text {
    
    
            id: txt
            text: qsTr("text");
            color: "white";
            anchors.centerIn: parent;
            font.pointSize: 24;
        }

        signal send();//自定义信号
        onSend: {
    
    
            num++;
            txt.text = num;
        }
        Button {
    
    
            id:btn;
            width: 200;
            height: 100;
            text: "button"
            anchors.horizontalCenter: rec.horizontalCenter;
            anchors.topMargin: 10;
            anchors.top: rec.bottom;
        }
        Component.onCompleted: {
    
    
            btn.clicked.connect(send);//clicked触发send信号
        }
    }
}