当currentIndex === -1时如何让StackLayout折叠？

Question

下面的代码只是做了一个简单的事情：点击时将

currentIndex

的

StackLayout

更改为

-1

。但我想让当

StackLayout

为

0

时，

currentIndex

的高度为

-1

。

Window {
    id: window
    width: 400
    height: 400
    visible: true
    color: "#181818"
    MouseArea {
        id: ma
        anchors.fill: parent
        hoverEnabled: true
        onClicked: lay.currentIndex = -1
    }

    StackLayout {
        id: lay
        anchors.top: parent.top
        Rectangle {
            width: 300
            height: 100
            color: "white"
        }
    }
    Rectangle {
        anchors.top: lay.bottom
        width: 200
        height: 100
        color: "red"
    }
}

我尝试过像这样的绑定

Binding {
    when: lay.currentIndex === -1
    lay.height: 0
}

但这行不通。

Answer 1

您可以收听内置

onCurrentIndexChanged

信号

import QtQuick 2.2
import QtQuick.Window 2.12
import QtQuick.Layouts 1.12

Window {
    id: window
    width: 400
    height: 400
    visible: true
    color: "#181818"
    MouseArea {
        id: ma
        anchors.fill: parent
        hoverEnabled: true
        onClicked:lay.currentIndex = -1
    }

    StackLayout {
        id: lay
        anchors.top: parent.top
        Rectangle {
            width: 300
            height: 100
            color: "white"
        }
        onCurrentIndexChanged: {
            if (lay.curentIndex === -1)
                lay.height = 0
        }
    }
    Rectangle {
        anchors.top: lay.bottom
        width: 200
        height: 100
        color: "red"
    }
}

刚刚在 Qt 5.12.8 上测试过