python - QTreeView 数据更改信号/插槽实现？

Question

我正在使用 pyqt5/python 3.7/win10，我有一个 QTreeView，它只有一个可编辑的列，可以很好地编辑。我现在需要做的是在按下回车键或输入键或由于在其他任何地方单击鼠标而失去焦点时告诉程序该字段已更改(或检查它是否已更改)。

我已经包含了一个简单的程序，它反射(reflect)了我到目前为止的全部情况及其所有层，我们选择了单击而不是双击来选择要编辑的字段。

我花了相当多的时间试图弄清楚这个问题，虽然我已经看到了可能的答案，但我还没有找到适合我的答案。我确信这可能相当简单，但我在实现该解决方案时花了不少时间。

from sys import exit as sysExit

from PyQt5.QtCore import *
from PyQt5.QtGui  import *
from PyQt5.QtWidgets import *

class CustomItemModel(QStandardItemModel):
    def headerData(self, section, orientation, role):
        if role == Qt.ForegroundRole:
            brush = QBrush()
            brush.setColor(Qt.blue)
            brush.setStyle(Qt.SolidPattern)
            return brush

        elif role == Qt.BackgroundRole:
            brush = QBrush()
            brush.setColor(Qt.yellow)
            brush.setStyle(Qt.SolidPattern)
            return brush

        elif role == Qt.FontRole:
            font = QFont()
            font.setBold(True)
            font.setPointSize(10)
            return font

        return super().headerData(section, orientation, role)

class ItemDsplyr(QTreeView):
    def __init__(self, CentrPane):
        QTreeView.__init__(self, CentrPane)
        self.CntrPane = CentrPane
        self.setEditTriggers(QTreeView().NoEditTriggers)
        self.model = CustomItemModel(0, 4)

        self.model.setHorizontalHeaderLabels(['', 'ItemName', 'Value', 'Units'])
        self.model.setHeaderData(2, Qt.Horizontal, Qt.AlignCenter, Qt.TextAlignmentRole)
        self.setModel(self.model)

        self.setColumnWidth(0, 1)  #Not sure what the minimum column width is but is greater than 1
        self.setColumnHidden(0, True)

        self.header().setSectionResizeMode(0, QHeaderView.Fixed)

        self.header().setStretchLastSection(False)
        self.header().setSectionResizeMode(1, QHeaderView.Stretch)
        self.setColumnWidth(2, 75)
        self.setColumnWidth(3, 100)

        self.clicked.connect(self.__itemSingleClicked)

    @property
    def CntrPane(self):
        return self.__parent

    @CntrPane.setter
    def CntrPane(self, value):
        self.__parent = value

    def SetContent(self, tmpItmList):
        self.model.setRowCount(0)

        for Item in tmpItmList:
            blnkVal = QStandardItem('')

            ItmNam = QStandardItem(Item['ItemName'])
            ItmNam.setTextAlignment(Qt.AlignLeft)
            ItmNam.isEditable = False

            ItmVal = QStandardItem(Item['Value'])
            ItmVal.setTextAlignment(Qt.AlignCenter)

            ItmUnt = QStandardItem((Item['Units']))
            ItmUnt.setTextAlignment(Qt.AlignLeft)
            ItmUnt.isEditable = False

            self.model.appendRow([blnkVal, ItmNam, ItmVal, ItmUnt])

    def __itemSingleClicked(self, index):
        Item = self.selectedIndexes()[0]
        CurRow = index.row()
        ItemIdx = index.sibling(CurRow, 1)
        ValuIdx = index.sibling(CurRow, 2)
        self.edit(ValuIdx)

        ItemVal = Item.model().itemFromIndex(ItemIdx).text()
        ValuVal = Item.model().itemFromIndex(ValuIdx).text()
        self.CntrPane.CurItemValue(ItemVal, ValuVal)

class CenterPanel(QWidget):
    def __init__(self, MainWin):
        QWidget.__init__(self)

        self.MainWin = MainWin
        self.ListItm = ''
        self.ListVal = ''

        ItmList = [
            {'ItemName':'Cal-Itm-1', 'Value':'54',  'Units':'Units'},
            {'ItemName':'Cal-Itm-2', 'Value':'54',  'Units':'Units'},
            {'ItemName':'Cal-Itm-1', 'Value':'10',  'Units':'Passes'},
            {'ItemName':'Cal-Itm-2', 'Value':'2.5', 'Units':'Volts'},
            {'ItemName':'Run-Itm-1', 'Value':'2',   'Units':'Units'},
            {'ItemName':'Run-Itm-2', 'Value':'1',   'Units':'Units'},
            {'ItemName':'Run-Itm-1', 'Value':'10',  'Units':'Units'},
            {'ItemName':'Run-Itm-2', 'Value':'50',  'Units':'Units'},
            {'ItemName':'Tbl-Itm-1', 'Value':'0',   'Units':'Units'},
            {'ItemName':'Tbl-Itm-2', 'Value':'0',   'Units':'Units'},
            {'ItemName':'Tbl-Itm-1', 'Value':'0',   'Units':'Units'},
            {'ItemName':'Tbl-Itm-2', 'Value':'255', 'Units':'Units'}
            ]

        self.CatGrpTree = QTextEdit()

        self.ItemDsply = ItemDsplyr(self)
        self.ItemDsply.SetContent(ItmList)

        CntrPane = QSplitter(Qt.Horizontal, self)
        CntrPane.addWidget(self.CatGrpTree)
        CntrPane.addWidget(self.ItemDsply)
        CntrPane.setSizes([50,200])

        hbox = QHBoxLayout(self)
        hbox.addWidget(CntrPane)

        self.setLayout(hbox)

    @property
    def MainWin(self):
        return self.__parent

    @MainWin.setter
    def MainWin(self, value):
        self.__parent = value

    def CurItemValue(self, LstItm, LstVal):
        print("List Item/Value Clicked:",LstItm,"/",LstVal)
        if LstItm != self.ListItm:
            self.ListItm = LstItm
            self.ListVal = LstVal

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

        self.title = 'Main Window'
        self.left = 100
        self.ztop = 100
        self.wide = 700
        self.high = 600

        self.InitGUI()

    def InitGUI(self):
        self.setWindowTitle(self.title)
        self.setGeometry(self.left, self.ztop, self.wide, self.high)

        self.CenterPane = CenterPanel(self)
        self.setCentralWidget(self.CenterPane)

        self.setStyle(QStyleFactory.create('Cleanlooks'))

if __name__ == "__main__":
    MainApp = QApplication([])
    # This fixes a display issue with Windows
    MainApp.setStyle("fusion")

    MainGUI = Window()
    MainGUI.show()

    sysExit(MainApp.exec_())

可以看出(在运行时)您会得到一个 QTreeView(大部分只是一个列表，但根据我的研究，QTreeView 是最好使用的)。如果您单击一行，您会立即在“值”列中进入编辑模式。但是我无法确定如何知道何时检查字段是否已更改(我正在捕获预编辑的值)。因此，On-Lost-Focus 就足够了，但 Data-Changed 会更好。

Answer 1

如果你想得到项目的文本，如果它只是被改变了，那么你必须使用 dataChanged(...)信号

# ...
class ItemDsplyr(QTreeView):
    def __init__(self, CentrPane):
        QTreeView.__init__(self, CentrPane)
        # ...
        self.model.setHeaderData(2, Qt.Horizontal, Qt.AlignCenter, Qt.TextAlignmentRole)
        self.model.dataChanged.connect(self.on_data_changed)
        # ...

    @pyqtSlot("QModelIndex", "QModelIndex", "QVector<int>")
    def on_data_changed(self, top_left, bottom_right, roles):
        if top_left == bottom_right and Qt.DisplayRole in roles:
            print(top_left.data())
# ...