Qml绑定特性

import QtQuick 2.0

Rectangle {
    property int i: 0
    width: 640
    height: 480

    Text {
        text: changed()
    }

    Timer {
        interval: 1000; running: true; repeat: true
        onTriggered: i++
    }

    function changed() {
        return i
    }
}