动态连接到动态创建对象的信号 [英] Connect dynamically to signals of dynamically created objects

问题描述

标题可能有点混乱，但我的意图很简单:

我有一个 [Repeater/Instantiator] 可以创建任意委托的多个实例.我想对委托实例的属性(只有第一级，因此没有属性的属性)的所有更改做出反应，调用函数

function update(index, propertyName)

这似乎很容易，但我失败了.这是我的代码

<块引用>

TestObj.qml

中继器{onItemAdded: {var 键 = Object.keys(item)控制台日志(键)for (var k = 0; k 

<块引用>

main.qml:

导入 QtQuick 2.7导入 QtQuick.Controls 2.0导入 QtQml 2.2将 QtQuick.Controls 1.4 导入为 Ctrl进口 '.'导入test.js"作为测试应用程序窗口{身份证:根可见:真实最小宽度:500最小高度:500属性 var blub: []柱子 {间距:5测试对象{型号:5委托:行{间距:2属性 int p1: 0属性 int p2: 2属性 int p3: 4按钮 {文字:parent.p1onClicked:parent.p1++}按钮 {文字:parent.p2onClicked: parent.p2 *= 2}按钮 {文字:parent.p3onClicked: parent.p3 *= parent.p3}}}}}

它成功连接了某些东西，但我无法正确锁定 key.无论我更改哪个属性，我总是得到信息，我在示例中更改了属性 p3.

如何锁定密钥，以便在更改具有相应名称的属性时获得propertyName?

解决方案

一种可能的解决方案是，创建一个具有该功能的对象，然后只分配该功能

中继器{onItemAdded: {var 键 = Object.keys(item)for (var k = 0; k 

但也许有更好的解决方案等待公开?

The title might be a bit confusing, but my intent is pretty simple:

I have a [Repeater/Instantiator] which creates multiple instances of a arbitrary delegate. I want to react to all changes of the properties (only first-level, so no properties of properties) of the instances of the delegate, calling a function

function update(index, propertyName)

This seems to be easy, but I fail. This is my code

TestObj.qml

Repeater {
    onItemAdded: {
        var keys = Object.keys(item)
        console.log(keys)
        for (var k = 0; k < keys.length; k++) {
            if (item[keys[k] + 'Changed'] !== undefined  && keys[k] !== 'objectName') {
                var key = keys[k]
                var str = "function() { console.log('Property, " + key + " of " + index + " changed') }"
                console.log(str)
                item[key + 'Changed'].connect(function() { console.log('Property', key, 'of', index, 'changed') })
            }
        }
    }
}

main.qml:

import QtQuick 2.7
import QtQuick.Controls 2.0
import QtQml 2.2
import QtQuick.Controls 1.4 as Ctrl
import '.'
import 'test.js' as Test

ApplicationWindow {
    id: root
    visible: true
    minimumWidth: 500
    minimumHeight: 500
    property var blub: []

    Column {
        spacing: 5
        TestObj {
            model: 5
            delegate: Row {
                spacing: 2
                property int p1: 0
                property int p2: 2
                property int p3: 4

                Button {
                    text: parent.p1
                    onClicked: parent.p1++
                }
                Button {
                    text: parent.p2
                    onClicked: parent.p2 *= 2
                }
                Button {
                    text: parent.p3
                    onClicked: parent.p3 *= parent.p3
                }
            }
        }
    }
}

It succesfully connects something, but I can't get the key properly locked. Whichever property I change, I always get the info, I had changed property p3 in my example.

How can I lock the key, so that I get propertyName when I change the the property with the corresponding name?

解决方案

One possible solution is, to create an object that has the function, and then just assign this function

Repeater {
    onItemAdded: {
        var keys = Object.keys(item)
        for (var k = 0; k < keys.length; k++) {
            if (item[keys[k] + 'Changed'] !== undefined  && keys[k] !== 'objectName') {
                var key = keys[k]
                var f = __funproto.createObject(this, { i: index, n: key })
                item[key + 'Changed'].connect(f.fun)
            }
        }
    }
}

Component {
    id: __funproto
    QtObject {
        property int i
        property string n
        function fun() { /*do something with it!*/}
    }
}

But maybe there is a even better solution waiting to be disclosed?

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