点击QRadioButton时Python崩溃，无法加载数据库球员列表到QListWidget

我帮你梳理了代码里几个导致崩溃的核心问题，逐个修复后就能正常运行了：

1. 信号与槽的参数不匹配 #

QButtonGroup的buttonToggled信号会传递两个参数：被切换的按钮对象和是否被选中的布尔值，但你的showList函数只定义了一个不相关的MainWindow参数，这会直接触发参数不匹配的致命错误。

修改showList的函数签名，并且只在按钮被选中时执行逻辑（避免切换时重复触发两次）：

def showList(self, button, checked):
    if not checked:
        return  # 只处理按钮被选中的情况，忽略取消选中的信号
    # 后续逻辑...

2. 数据库查询结果处理错误 #

cur.fetchall()返回的是元组列表（比如[('PlayerA',), ('PlayerB',)]），而listWidget.addItems()接收的是字符串序列。你现在用addItems(row)会把元组里的每个字符当成单独的列表项，这不仅不符合预期，还可能引发内部错误。

应该改用addItem()并取出元组的第一个元素：

records = self.cur.fetchall()
self.listWidget.clear()
for row in records:
    self.listWidget.addItem(row[0])  # 取出元组中的球员名称
# 不需要调用update()，addItem/clear会自动刷新界面

3. 数据库连接的线程安全问题 #

你在全局初始化了数据库连接和游标，但PyQt的UI操作在主线程，全局连接可能会因为线程上下文冲突导致崩溃。建议把数据库连接移到类内部，比如在自定义窗口类中初始化：

class MainWindow(QtWidgets.QMainWindow, Ui_MainWindow):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.setupUi(self)
        # 初始化数据库连接
        self.db = sqlite3.connect("fantcktdb.db")
        self.cur = self.db.cursor()
    
    def closeEvent(self, event):
        # 窗口关闭时关闭数据库连接
        self.cur.close()
        self.db.close()
        event.accept()

4. 添加异常捕获避免崩溃 #

为了防止数据库操作出错导致程序崩溃，可以在查询逻辑中加入异常捕获：

def showList(self, button, checked):
    if not checked:
        return
    self.listWidget.clear()
    try:
        if button == self.batRadio:
            self.cur.execute('''SELECT Player FROM stats WHERE Ctg='BAT';''')
        elif button == self.bowRadio:
            self.cur.execute('''SELECT Player FROM stats WHERE Ctg='BOW';''')
        elif button == self.arRadio:
            self.cur.execute('''SELECT Player FROM stats WHERE Ctg='AR';''')
        elif button == self.wkRadio:
            self.cur.execute('''SELECT Player FROM stats WHERE Ctg='WK';''')
        records = self.cur.fetchall()
        for row in records:
            self.listWidget.addItem(row[0])
    except Exception as e:
        print(f"数据库查询错误: {e}")

完整修复后的代码 #

整合所有修改后的完整代码如下：

from PyQt5 import QtCore, QtGui, QtWidgets
import sqlite3

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(800, 600)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.gridLayout = QtWidgets.QGridLayout(self.centralwidget)
        self.gridLayout.setObjectName("gridLayout")
        self.frame = QtWidgets.QFrame(self.centralwidget)
        self.frame.setFrameShape(QtWidgets.QFrame.StyledPanel)
        self.frame.setFrameShadow(QtWidgets.QFrame.Raised)
        self.frame.setObjectName("frame")
        self.gridLayout_2 = QtWidgets.QGridLayout(self.frame)
        self.gridLayout_2.setObjectName("gridLayout_2")
        self.verticalLayout = QtWidgets.QVBoxLayout()
        self.verticalLayout.setObjectName("verticalLayout")
        self.wkRadio = QtWidgets.QRadioButton(self.frame)
        self.wkRadio.setObjectName("wkRadio")
        self.buttonGroup = QtWidgets.QButtonGroup(MainWindow)
        self.buttonGroup.setObjectName("buttonGroup")
        self.buttonGroup.addButton(self.wkRadio)
        self.verticalLayout.addWidget(self.wkRadio)
        self.arRadio = QtWidgets.QRadioButton(self.frame)
        self.arRadio.setObjectName("arRadio")
        self.buttonGroup.addButton(self.arRadio)
        self.verticalLayout.addWidget(self.arRadio)
        self.bowRadio = QtWidgets.QRadioButton(self.frame)
        self.bowRadio.setObjectName("bowRadio")
        self.buttonGroup.addButton(self.bowRadio)
        self.verticalLayout.addWidget(self.bowRadio)
        self.batRadio = QtWidgets.QRadioButton(self.frame)
        self.batRadio.setObjectName("batRadio")
        self.buttonGroup.addButton(self.batRadio)
        self.verticalLayout.addWidget(self.batRadio)
        self.buttonGroup.buttonToggled.connect(self.showList)
        self.listWidget = QtWidgets.QListWidget(self.frame)
        self.listWidget.setObjectName("listWidget")
        self.verticalLayout.addWidget(self.listWidget)
        self.gridLayout_2.addLayout(self.verticalLayout, 0, 0, 1, 1)
        self.gridLayout.addWidget(self.frame, 0, 0, 1, 1)
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 800, 26))
        self.menubar.setObjectName("menubar")
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)
        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def showList(self, button, checked):
        if not checked:
            return
        self.listWidget.clear()
        try:
            if button == self.batRadio:
                self.cur.execute('''SELECT Player FROM stats WHERE Ctg='BAT';''')
            elif button == self.bowRadio:
                self.cur.execute('''SELECT Player FROM stats WHERE Ctg='BOW';''')
            elif button == self.arRadio:
                self.cur.execute('''SELECT Player FROM stats WHERE Ctg='AR';''')
            elif button == self.wkRadio:
                self.cur.execute('''SELECT Player FROM stats WHERE Ctg='WK';''')
            records = self.cur.fetchall()
            for row in records:
                self.listWidget.addItem(row[0])
        except Exception as e:
            print(f"错误: {e}")

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.wkRadio.setText(_translate("MainWindow", "WK"))
        self.arRadio.setText(_translate("MainWindow", "AR"))
        self.bowRadio.setText(_translate("MainWindow", "BOW"))
        self.batRadio.setText(_translate("MainWindow", "BAT"))

class MainWindow(QtWidgets.QMainWindow, Ui_MainWindow):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.setupUi(self)
        # 初始化数据库连接
        self.db = sqlite3.connect("fantcktdb.db")
        self.cur = self.db.cursor()

    def closeEvent(self, event):
        # 关闭数据库连接
        self.cur.close()
        self.db.close()
        event.accept()

if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    window = MainWindow()
    window.show()
    sys.exit(app.exec_())

这些修改应该能彻底解决你遇到的崩溃问题，同时让代码更健壮易维护。

内容的提问来源于stack exchange，提问作者Tejaswini Nimbalkar