python - 如何在 ListView 中选择行

Question

我在网上搜索，但没有找到如何使用 python 在 qml 文件中创建的 ListView 中选择一行。我测试过，但每次都会出错。我刚开始qml，也许基础不好。所以我的问题是，使用我的代码，可以访问我的 ListView 吗？如果是，我如何在启动应用程序中选择第二项(例如)？

当我这样做时:

print(win.findChild(QObject, "listview22").setCurrentIndex(2)))

我有这条消息

AttributeError: 'QQuickItem' object has no attribute 'setCurrentIndex'

但是listview22是一个 ListView 而不是一个项目。

感谢您的帮助。

PS:我刚刚启动 qml，所以如果我的脚本不好请告诉我，然后我可以学习好的编程

main.qml

import QtQuick 2.4
import QtQuick.Controls 1.3
import QtQuick.Layouts 1.1

ApplicationWindow {
    title: qsTr("WoodMan Training")

    width: 1000
    height: 700

    visible: true

    GridLayout {
        id: grid
        anchors.fill: parent
        columns: 3
        anchors.margins: 0
        columnSpacing: 0

        ColumnLayout {
            Layout.columnSpan: 1
            Layout.row: 2
            Layout.column: 0
            Layout.fillWidth: true
            Layout.fillHeight: true

            Layout.margins: 10

            Layout.maximumWidth: 250

                // ---
            RowLayout{
            Main_ListView{objectName: "lstGroupe"; id:lstGroupe; pyModel: ModelGroupe; pyClass: ModelGroupe}
            }       

            Item {Layout.fillWidth: true; Layout.fillHeight: true}

        }
     }  
}

Main_ListView.qml

import QtQuick 2.4
import QtQuick.Controls 1.3
import QtQuick.Layouts 1.1
import QtQuick.Window 2.2

Rectangle {
    property var pyClass: 0
    property var pyModel: 0


    border.color: "red"
    Layout.fillWidth: true
    height:150


    ListView {
        anchors.topMargin: 10
        anchors.bottomMargin: 10
        anchors.leftMargin: 10
        anchors.fill: parent

        id: listview22
        objectName: "listview22"

        model: pyModel
        clip: true                                                      // --- Empeche la surbrillance de sortir du cadre

        delegate: Component {
            Item {
                width: 200
                height: 20

                property int item_id: iid

                Row {
                    Text {
                        anchors.verticalCenter: parent.verticalCenter

                        width: 60
                        text:  "  " + libelle
                    }
                }

                MouseArea {
                    anchors.fill: parent
                    onClicked: {
                        listview22.currentIndex = index
                        pyClass.onClickItem(item_id)                        
                    }
                }               

            }
        }
        highlight: Rectangle {color: '#CDCDCD'}
        focus: true     
    }

    Button {
        anchors.bottom: parent.bottom              
        anchors.right: parent.right
        anchors.rightMargin: 5
        anchors.bottomMargin: 5

        width: 28
        height: 25

        iconSource: "ico/math-add-icon.png"

        onClicked: {
            //console.log("qml adding")
            pyClass.onClickInsert(22, "aluis")
        }
    }

}

主程序.py

from PyQt5.QtCore import QAbstractListModel, Qt, pyqtSignal, pyqtSlot, QModelIndex    

import sys
from PyQt5.QtCore import QUrl
from PyQt5.QtWidgets import QApplication
from PyQt5.QtQuick import QQuickView

from PyQt5.QtGui import *#QGuiApplication, QColor, QStandardItemModel, QStandardItem
from PyQt5.QtQml import *#QQmlApplicationEngine, QQmlComponent
from PyQt5.QtCore import *#QUrl, Qt, QCoreApplication, QAbstractListModel, QModelIndex, QTimer, qsrand, qrand, QTime, QObject
from PyQt5.QtQuick import *#QQuickItem



class gGroupe(QAbstractListModel):


    iid = Qt.UserRole + 1
    libelle = Qt.UserRole + 2

    data_change = pyqtSignal()

    def __init__(self, parent=None):

        super().__init__(parent)

        self.liste = []
        self.insert_list()

        self.liste2 = {}

        self.createIndex(0,0,125)
        self.sort(1, order = Qt.DescendingOrder)


    # ------------------------------------------------------------------

    def roleNames(self):
        return {
            gGroupe.iid: b'iid',
            gGroupe.libelle: b'libelle',
        }

    def data(self, index, role=Qt.DisplayRole):
        row = index.row()
        if role == gGroupe.iid:
            return self.liste[row]["iid"]
        if role == gGroupe.libelle:
            return self.liste[row]["libelle"]

    def rowCount(self, parent=QModelIndex()):
        return len(self.liste)

    # ------------------------------------------------------------------

    def insert_list(self):

        self.liste = [
            {'iid': 10, 'libelle': 'groupe10'},
            {'iid': 11, 'libelle': 'groupe11'},
            {'iid': 12, 'libelle': 'groupe12'},
        ]


    def delete(self, row):
        self.beginRemoveRows(QModelIndex(), row, row)
        del self.liste[row]
        self.endRemoveRows()  

    def delete_all(self):
        self.beginRemoveRows(QModelIndex(), 0, len(self.liste))
        del self.liste[row]
        self.endRemoveRows()  

    def select(self):
        pass

    @pyqtSlot(int, str)
    def onClickInsert(self, iid=10, libelle='toto'):

        self.beginInsertRows(QModelIndex(), self.rowCount(), self.rowCount())
        self.liste.append({'iid': iid, 'libelle': libelle})
        self.endInsertRows()

        return self.index(len(self.liste)-1)

    @pyqtSlot(int)
    def onClickItem(self, iid):
        print(iid)

    """
    @pyqtSlot(int, str, int)
    def editPerson(self, row, name, age):
        ix = self.index(row, 0)
        self.persons[row] = {'iid': 22, 'name': name, 'age': age}
        self.dataChanged.emit(ix, ix, self.roleNames())
    """


class MainWindow(QObject):
    def __init__(self, parent=None):
        super().__init__(parent)

        self.g_groupe = gGroupe()
        engine.rootContext().setContextProperty('ModelGroupe', self.g_groupe)

        engine.load('main.qml')
        win = engine.rootObjects()[0]

        #win.findChild(QObject, "txtLibelle").setProperty("text", 'toto')

        print(win.findChild(QObject, "listview22").setCurrentIndex(2))

        a = win.findChild(QObject, "PersonModel")#.removeRows( 0, model.rowCount() )


if __name__ == "__main__":
    app = QApplication(sys.argv)
    engine = QQmlApplicationEngine()
    # Création d'un objet QQmlContext pour communiquer avec le code QML
    #ctx = engine.rootContext()
    py_mainapp = MainWindow()
    sys.exit(app.exec())

Answer 1

您有以下错误:

• 您不应该将 QML 对象导出到 python，因为它会给您带来许多像您遇到的错误，甚至更严重的错误，这是 C++ 中推荐的。

• 当尝试在 C++ 中使用 findChild (QObject, "listview22") 获取 ListView 时，只会获取一个 QObject，但 python 会尝试推断类型，为此它具有 Qt 的公共(public) API 作为限制，在您的 ListView 中，它不是 QListView，并且它的类型在 Python 或 C++ 中不存在，因为它是私有(private) API 的一部分，因此附近的类是 QQuickItem，因为 ListView 继承自该类。

建议创建一个 QObject 并添加映射逻辑并导出到 QML 的 qproperties，因此，如果您在 python 中修改 QObject，它也会在 QML 中修改它。

ma​​in.py

from PyQt5.QtCore import (
    pyqtProperty,
    pyqtSignal,
    pyqtSlot,
    QAbstractListModel,
    QModelIndex,
    QObject,
    Qt,
    QTimer,
)
from PyQt5.QtGui import QGuiApplication
from PyQt5.QtQml import QQmlApplicationEngine


class gGroupe(QAbstractListModel):

    iid = Qt.UserRole + 1
    libelle = Qt.UserRole + 2

    data_change = pyqtSignal()

    def __init__(self, parent=None):
        super().__init__(parent)

        self.liste = []
        self.insert_list()

        self.sort(0, order=Qt.DescendingOrder)

    def roleNames(self):
        return {gGroupe.iid: b"iid", gGroupe.libelle: b"libelle"}

    def data(self, index, role=Qt.DisplayRole):
        row = index.row()
        if role == gGroupe.iid:
            return self.liste[row]["iid"]
        if role == gGroupe.libelle:
            return self.liste[row]["libelle"]

    def rowCount(self, parent=QModelIndex()):
        return len(self.liste)

    # ------------------------------------------------------------------

    def insert_list(self):
        self.beginResetModel()
        self.liste = [
            {"iid": 10, "libelle": "groupe10"},
            {"iid": 11, "libelle": "groupe11"},
            {"iid": 12, "libelle": "groupe12"},
        ]
        self.endResetModel()

    def delete(self, row):
        self.beginRemoveRows(QModelIndex(), row, row)
        del self.liste[row]
        self.endRemoveRows()

    def delete_all(self):
        self.beginRemoveRows(QModelIndex(), 0, len(self.liste))
        del self.liste[row]
        self.endRemoveRows()

    def select(self):
        pass

    @pyqtSlot(int, str)
    def insert(self, iid=10, libelle="toto"):
        self.beginInsertRows(QModelIndex(), self.rowCount(), self.rowCount())
        self.liste.append({"iid": iid, "libelle": libelle})
        self.endInsertRows()

    @pyqtSlot(int)
    def onClickItem(self, iid):
        print(iid)


class MainWindow(QObject):
    currentIndexChanged = pyqtSignal(int)

    def __init__(self, parent=None):
        super().__init__(parent)
        self._g_groupe = gGroupe(self)
        self._current_index = 0

    @pyqtProperty(QObject, constant=True)
    def g_groups(self):
        return self._g_groupe

    @pyqtProperty(int, notify=currentIndexChanged)
    def currentIndex(self):
        return self._current_index

    @currentIndex.setter
    def currentIndex(self, index):
        if self._current_index == index:
            return
        self._current_index = index
        self.currentIndexChanged.emit(index)

if __name__ == "__main__":
    import sys

    app = QGuiApplication(sys.argv)
    engine = QQmlApplicationEngine()
    main_window = MainWindow()
    engine.rootContext().setContextProperty("main_window", main_window)
    engine.load("main.qml")
    if not engine.rootObjects():
        sys.exit(app.exec_())

    main_window.currentIndex = 2

    sys.exit(app.exec())

ma​​in.qml

import QtQuick 2.4
import QtQuick.Controls 1.3
import QtQuick.Layouts 1.1

ApplicationWindow {
    title: qsTr("WoodMan Training")

    width: 1000
    height: 700

    visible: true

    Connections{
        target: main_window
        onCurrentIndexChanged: lstGroupe.currentIndex = main_window.currentIndex
    }

    GridLayout {
        id: grid
        anchors.fill: parent
        columns: 3
        anchors.margins: 0
        columnSpacing: 0

        ColumnLayout {
            Layout.columnSpan: 1
            Layout.row: 2
            Layout.column: 0
            Layout.fillWidth: true
            Layout.fillHeight: true

            Layout.margins: 10

            Layout.maximumWidth: 250

                // ---
            RowLayout{
                Main_ListView{
                    id:lstGroupe; 
                    model: main_window.g_groups
                }
            }       

            Item {
                Layout.fillWidth: true
                Layout.fillHeight: true
            }
        }
    }  
}

Main_ListView.qml

import QtQuick 2.4
import QtQuick.Controls 1.3
import QtQuick.Layouts 1.1
import QtQuick.Window 2.2

Rectangle {
    id: root
    property alias model: listview22.model
    property alias currentIndex: listview22.currentIndex

    border.color: "red"
    Layout.fillWidth: true
    height:150

    ListView {
        id: listview22
        model: root.model
        anchors.topMargin: 10
        anchors.bottomMargin: 10
        anchors.leftMargin: 10
        anchors.fill: parent
        clip: true

        delegate: Component {
            Item {
                width: 200
                height: 20
                property int item_id: iid
                Row {
                    Text {
                        anchors.verticalCenter: parent.verticalCenter
                        width: 60
                        text:  "  " + libelle
                    }
                }
                MouseArea {
                    anchors.fill: parent
                    onClicked: {
                        listview22.currentIndex = index
                        listview22.model.onClickItem(item_id)                        
                    }
                }               
            }
        }
        highlight: Rectangle {color: '#CDCDCD'}
        focus: true     
    }
    Button {
        anchors.bottom: parent.bottom              
        anchors.right: parent.right
        anchors.rightMargin: 5
        anchors.bottomMargin: 5
        width: 28
        height: 25
        iconSource: "ico/math-add-icon.png"
        onClicked: {
            listview22.model.insert(22, "aluis")
        }
    }
}