Qt 5.4 QML 信号槽

Question

import QtQuick 2.0  
import QtQuick.Controls 1.1  
  
Rectangle {  
    width: 320;  
    height: 240;  
    color: "gray";  	//窗口底色：灰色
      
    Text {  
        id: text1;  
        anchors.horizontalCenter: parent.horizontalCenter;  //居中显示
        anchors.top: parent.top;  
        anchors.topMargin: 20;  
        text: "Text One";  
        color: "blue";  
        font.pixelSize: 28;  
    }  
      
    Text {  
        id: text2;  
        anchors.horizontalCenter: parent.horizontalCenter;  
        anchors.top: text1.bottom;  
        anchors.topMargin: 8;  
        text: "Text Two";  
        color: "blue";  
        font.pixelSize: 28;  
    }  
      
    Button {  
        id: changeButton;  
        anchors.top: text2.bottom;  
        anchors.topMargin: 8;  
        anchors.horizontalCenter: parent.horizontalCenter;  
        text: "Change";  
    }  
      
    Connections {  
        target: changeButton;  
        onClicked: {  
            text1.color = Qt.rgba(Math.random(), Math.random(), Math.random(), 1); //颜色随机
            text2.color = Qt.rgba(Math.random(), Math.random(), Math.random(), 1);  	
        }  
    }  
}  

// Math 是 JavaScript 语言内置的对象，有 random() / sin() / max() / min() / abs() 等等方法