QTableWidget.itemAt() 的最后一行返回 None 而不是 QTableWidgetItem

Question

我正在使用 PyQt5 制作一个在表格中显示数据的 GUI。我想在按下“右键单击”时在特定光标位置获取项目。这是使用 contextMenuEvent 函数实现的，适用于除最后一行之外的所有行。单击表格的最后一行时，它会打印“无”而不是 QTableWidgetItem 对象。

我很困惑为什么它应该返回最后一个 QTableWidgetItem 时返回 None。

我尝试修改 event.pos() 并将其更改为 globalPos()，认为坐标可能错误，但没有任何效果。

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


class CollectWindow(QMainWindow):
    def __init__(self): # window properties
        super().__init__()

        # create window
        self.setGeometry(0,0, 800, 600)
        self.centralWidget = QtWidgets.QWidget()
        self.horizontalLayout = QtWidgets.QHBoxLayout(self.centralWidget)
        self.setCentralWidget(self.centralWidget)

        # create table display 
        self.table = QtWidgets.QTableWidget()
        self.horizontalLayout.addWidget(self.table)
        self.table.setColumnCount(7)
        self.table.setHorizontalHeaderLabels(["Exam Remark", "Preop", "Appt Time", "Patient Details", "Exam", "Ward", "Bed"])

        # load data into table
        self.getData()

        # show the window
        self.showMaximized()

    def contextMenuEvent(self, event):

        print (self.table.itemAt(event.pos()))

    def getData(self):

        # retrieve data from database
        result = [('Phil', 'Jones', 11256675, '08/09/1994', '09:40', '10:00', '09', '912', 'CT Pulmonary Angio', None, 'A', 'Clark Bed Bay', 'Arrived'), 
        ('Max', 'Stevenson', 11256676, '07/05/1965', '09:10', '09:30', '12', '1231', 'ECHO TTE', 'Rebook for Tommorow', 'PX', 'Tulloch 3 Bed Bay', 'Procedure Cancelled'), 
        ('Alfred', 'Bosch', 11256677, '01/01/1976', '09:40', '10:00', 'CLK9', 'CLK914', 'MRI Lumbar Spine', None, 'NP', 'Clark Bed Bay', 'Nurse Preparation'), 
        ('Gwenda', 'Gull', 11256678, '17/06/1956', '08:55', '09:15', 'EC', '03', 'XRAY Chest', None, 'F', 'Tulloch 2 Bed Bay', 'Exam Finished'), 
        ('John', 'Stalwort', 11256679, '15/07/1977', '12:00', '12:30', 'CLK8', 'CLK831', 'MRI Whole Spine', None, None, None, 'Created'), 
        ('Peter', 'Fitzgibbons', 11256680, '17/04/1944', '12:00', '12:30', '07', '733', 'CT Chest Abdomen Pelvis', 'Hold', None, None, 'Created'), 
        ('Julie', 'Bishop', 11256681, '15/6/1977', '12:30', '12:45', '09', '931', 'XRAY Chest', '', '', '', 'Created')]

        self.table.setRowCount(0)
        # plug data into table
        for row_number, row_data in enumerate(result):
            self.table.insertRow(row_number)

            examRemark = '' if row_data[9] is None else row_data[9]
            preopTime = '' if row_data[4] is None else row_data[4]
            apptTime = '' if row_data[5] is None else row_data[5]
            patientDetails = row_data[1] + ", " + row_data[0] + " - " + row_data[3] + " - " + str(row_data[2]) 
            exam = '' if row_data[8] is None else row_data[8]
            ward = '' if row_data[6] is None else row_data[6]
            bed = '' if row_data[7] is None else row_data[7]

            self.table.setItem(row_number, 0, QtWidgets.QTableWidgetItem(str(examRemark)))
            self.table.setItem(row_number, 1, QtWidgets.QTableWidgetItem(str(preopTime)))
            self.table.setItem(row_number, 2, QtWidgets.QTableWidgetItem(str(apptTime)))
            self.table.setItem(row_number, 3, QtWidgets.QTableWidgetItem(str(patientDetails)))
            self.table.setItem(row_number, 4, QtWidgets.QTableWidgetItem(str(exam)))
            self.table.setItem(row_number, 5, QtWidgets.QTableWidgetItem(str(ward)))
            self.table.setItem(row_number, 6, QtWidgets.QTableWidgetItem(str(bed)))


app = QApplication(sys.argv)
win = CollectWindow()
sys.exit(app.exec_())

Answer 1

event.pos() 包含光标在QMainWindow 坐标系中的位置。方法itemAt 需要在您的表格视口坐标系中的位置。

您必须使用类似的方法将事件中的位置映射到正确的坐标系：

    def contextMenuEvent(self, event):
        positionRelativeToMainWindow = event.pos()
        positionRelativeToViewport = self.table.viewport().mapFrom(self, positionRelativeToMainWindow)
        i = self.table.itemAt(positionRelativeToViewport)
        print(i.data(Qt.DisplayRole))