Rectangle {
    width: 100
    height: 100

    property int myValue: 0

    onMyValueChanged: {
        console.log("myValue changed from", PropertyChanges(myValue).from, "to", myValue)
    }

    MouseArea {
        anchors.fill: parent
        onClicked: myValue++
    }
}

上面是一个获取已经改变的属性的值

• PropertyChanges().from 获取之前的value