Qt 如何正确对齐qml组件？

我正在尝试编写简单的QML应用程序，它将由许多重复的元素组成，按行组织。结果将与下文所述类似：

目前，我有一段重复的代码实现了这个目标：

import QtQuick 2.12
import QtQuick.Window 2.12
import QtQuick.Controls 2.5
import QtQuick.Controls.Material 2.3
import QtQuick.Layouts 1.12

ApplicationWindow {
    Material.theme: Material.Dark
    visible: true
    width: 480
    height: 640
    title: qsTr("Hello world!")
    id: root

    GridLayout {
        anchors.horizontalCenter: parent.horizontalCenter
        columns: 3

        Text {
            color: "white"
            text: "aaa"
            font.family: "Ubuntu"
            font.pixelSize: 20
        }
        SpinBox {
            from: 0
            to: 1000
            stepSize: 1
            editable: true
        }
        Rectangle {
            width: 40
            height: 20
            color: "#F48FB1"
            Text {
                font.family: "Ubuntu"
                font.pixelSize: 16
                text: "ml"
                anchors.verticalCenter: parent.verticalCenter
                anchors.horizontalCenter: parent.horizontalCenter
            }
        }

        Text {
            color: "white"
            text: "bbb"
            font.family: "Ubuntu"
            font.pixelSize: 20
        }
        SpinBox {
            from: 0
            to: 100
            stepSize: 1
            editable: true
        }
        Rectangle {
            width: 40
            height: 20
            color: "#F48FB1"
            Text {
                font.family: "Ubuntu"
                font.pixelSize: 16
                text: "%"
                anchors.verticalCenter: parent.verticalCenter
                anchors.horizontalCenter: parent.horizontalCenter
            }
        }
        Text {
            color: "white"
            text: "ccc"
            font.family: "Ubuntu"
            font.pixelSize: 20
        }
        SpinBox {
            from: 0
            to: 100
            stepSize: 1
            editable: true
        }
        Rectangle {
            width: 40
            height: 20
            color: "#F48FB1"
            Text {
                font.family: "Ubuntu"
                font.pixelSize: 16
                text: "%"
                anchors.verticalCenter: parent.verticalCenter
                anchors.horizontalCenter: parent.horizontalCenter
            }
        }
    }
}

但是，每一行都有完全相同的结构，因此我尝试从代码中提取组件：

Item {
id: ingredient
property alias ingredientText: qualifier.text
property alias ingredientMaxValue: amount.to
property alias ingredientUnit: unit.text

RowLayout {
    Text {
        id: qualifier
        color: "white"
        text: "asdf"
        font.family: "Ubuntu"
        font.pixelSize: 20
    }
    SpinBox {
        id: amount
        from: 0
        to: 1000
        stepSize: 1
        editable: true
    }
    Rectangle {
        width: 40
        height: 20
        color: "#F48FB1"
        Text {
            id: unit
            font.family: "Ubuntu"
            font.pixelSize: 16
            text: "unit"
            anchors.verticalCenter: parent.verticalCenter
            anchors.horizontalCenter: parent.horizontalCenter
            }
        }
    }
}

不幸的是，当我尝试在主窗口中使用我的组件时，它没有对齐，并且脱离了它的可见部分（我可以在最大化窗口后再次看到它）：

---

问题是：如何使用“成分”组件实现第一张图片中的项目对齐？

您有以下错误：

• 您孩子的大小不用于计算物品的大小。要计算正确的大小，可以使用RowLayout的implicitWidth和implicitHeight
• 您不能使用GridLayout，因为正如您指出的，每个成分都是一个元素，在这种情况下，您必须使用ColumnLayout

成分。qml

import QtQuick 2.0
import QtQuick.Layouts 1.12
import QtQuick.Controls 2.5

Item {
    id: ingredient
    property alias ingredientText: qualifier.text
    property alias ingredientMaxValue: amount.to
    property alias ingredientUnit: unit.text

    width: rl.implicitWidth
    height: rl.implicitHeight

    RowLayout {
        id: rl
        Text {
            id: qualifier
            color: "white"
            text: "asdf"
            font.family: "Ubuntu"
            font.pixelSize: 20
        }
        SpinBox {
            id: amount
            from: 0
            to: 1000
            stepSize: 1
            editable: true
        }
        Rectangle {
            width: 40
            height: 20
            color: "#F48FB1"
            Text {
                id: unit
                font.family: "Ubuntu"
                font.pixelSize: 16
                text: "unit"
                anchors.verticalCenter: parent.verticalCenter
                anchors.horizontalCenter: parent.horizontalCenter
            }
        }
    }
}

import QtQuick 2.12
import QtQuick.Window 2.12
import QtQuick.Controls 2.5
import QtQuick.Controls.Material 2.3
import QtQuick.Layouts 1.12

ApplicationWindow {
    Material.theme: Material.Dark
    visible: true
    width: 480
    height: 640
    title: qsTr("Hello world!")
    id: root

    ColumnLayout{
        width: parent.width
        height: implicitHeight
        Ingredient{
            Layout.alignment: Qt.AlignHCenter
            ingredientMaxValue: 100; ingredientText: "qwerty"; ingredientUnit: "kg"
        }
        Ingredient{
            Layout.alignment: Qt.AlignHCenter
            ingredientMaxValue: 100; ingredientText: "qwerty"; ingredientUnit: "kg"
        }
        Ingredient{
            Layout.alignment: Qt.AlignHCenter
            ingredientMaxValue: 100; ingredientText: "qwerty"; ingredientUnit: "kg"
        }
    }

}

main.qml

import QtQuick 2.0
import QtQuick.Layouts 1.12
import QtQuick.Controls 2.5

Item {
    id: ingredient
    property alias ingredientText: qualifier.text
    property alias ingredientMaxValue: amount.to
    property alias ingredientUnit: unit.text

    width: rl.implicitWidth
    height: rl.implicitHeight

    RowLayout {
        id: rl
        Text {
            id: qualifier
            color: "white"
            text: "asdf"
            font.family: "Ubuntu"
            font.pixelSize: 20
        }
        SpinBox {
            id: amount
            from: 0
            to: 1000
            stepSize: 1
            editable: true
        }
        Rectangle {
            width: 40
            height: 20
            color: "#F48FB1"
            Text {
                id: unit
                font.family: "Ubuntu"
                font.pixelSize: 16
                text: "unit"
                anchors.verticalCenter: parent.verticalCenter
                anchors.horizontalCenter: parent.horizontalCenter
            }
        }
    }
}

import QtQuick 2.12
import QtQuick.Window 2.12
import QtQuick.Controls 2.5
import QtQuick.Controls.Material 2.3
import QtQuick.Layouts 1.12

ApplicationWindow {
    Material.theme: Material.Dark
    visible: true
    width: 480
    height: 640
    title: qsTr("Hello world!")
    id: root

    ColumnLayout{
        width: parent.width
        height: implicitHeight
        Ingredient{
            Layout.alignment: Qt.AlignHCenter
            ingredientMaxValue: 100; ingredientText: "qwerty"; ingredientUnit: "kg"
        }
        Ingredient{
            Layout.alignment: Qt.AlignHCenter
            ingredientMaxValue: 100; ingredientText: "qwerty"; ingredientUnit: "kg"
        }
        Ingredient{
            Layout.alignment: Qt.AlignHCenter
            ingredientMaxValue: 100; ingredientText: "qwerty"; ingredientUnit: "kg"
        }
    }

}

问题已解决。你应该读一下，这对你将来会有帮助的。你可以尝试尝试锚定，为你选择最佳的定位

简要介绍一下锚。锚点将自动设置项目的位置，以调整屏幕。此外，我还建议您阅读，以及

---

组件的根

项

没有大小，即其大小为0，因此布局将其放置在如此奇怪的位置。除此之外，这个东西在这里是完全无用的。