PyQt5 QHeaderView 子类化：实现自定义列宽限制与可见性问题解决

from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_Dialog(object):
    def setupUi(self, Dialog):
        Dialog.resize(400, 300)
        self.verticalLayout = QtWidgets.QVBoxLayout(Dialog)
        self.tableWidget = QtWidgets.QTableWidget(Dialog)
        self.tableWidget.setColumnCount(6)
        self.tableWidget.setRowCount(0) # 初始行数为0

        # 设置水平表头项
        headers = ["1", "2", "3", "4", "5", "6"]
        for i, text in enumerate(headers):
            item = QtWidgets.QTableWidgetItem()
            item.setText(text)
            self.tableWidget.setHorizontalHeaderItem(i, item)

        self.verticalLayout.addWidget(self.tableWidget)
        QtCore.QMetaObject.connectSlotsByName(Dialog)

from PyQt5 import QtWidgets, QtCore, QtGui
from table import Ui_Dialog
import sys

# 自定义QHeaderView类
class CustomHeader(QtWidgets.QHeaderView):
    def __init__(self, table, columns_min_width):
        self.columns_min_width = columns_min_width
        self.total_columns = len(self.columns_min_width)
        self.header_labels = []

        # 获取原始表头文本
        for column_index in range(self.total_columns):
            column_text = table.horizontalHeaderItem(column_index).text()
            self.header_labels.append(column_text)

        super().__init__(QtCore.Qt.Horizontal, table) # 调用父类构造函数
        self.table = self.parentWidget() # 获取QTableWidget的引用

        # 重新设置表头文本，确保正确显示
        for column_index in range(self.total_columns):
            header_item = self.table.horizontalHeaderItem(column_index)
            if header_item: # 检查header_item是否为None
                header_item.setText(self.header_labels[column_index])
            else:
                # 如果没有item，则创建一个
                new_item = QtWidgets.QTableWidgetItem(self.header_labels[column_index])
                self.table.setHorizontalHeaderItem(column_index, new_item)

        self.track_move = False # 标记是否正在拖动
        self.move_cancelled = False # 标记拖动是否被最小宽度限制取消
        self.index_cancelled = -1 # 记录被取消拖动的列索引
        self.setVisible(True) # 关键：确保自定义表头可见
        self.updateGeometries() # 更新几何布局

    def mousePressEvent(self, event):
        self.track_move = True
        self.click_x = event.pos().x() # 记录鼠标按下时的X坐标
        super().mousePressEvent(event)

    def mouseMoveEvent(self, event):
        self.moved_x = event.pos().x() # 记录鼠标移动时的X坐标
        if self.track_move:
            self.move_cancelled = False
            for column_index in range(self.total_columns):
                column_width = self.table.columnWidth(column_index)

                # 如果当前列宽小于或等于最小宽度
                if self.move_cancelled == False and column_width <= self.columns_min_width[column_index]:
                    event.ignore() # 忽略默认的拖动事件
                    self.table.setColumnWidth(column_index, self.columns_min_width[column_index]) # 强制设置为最小宽度
                    self.move_cancelled = True
                    self.index_cancelled = column_index
                    # 将该列的调整模式设置为固定，防止继续缩小
                    self.setSectionResizeMode(column_index, QtWidgets.QHeaderView.Fixed)
                elif self.move_cancelled and column_index == self.index_cancelled:
                    # 如果之前被取消拖动的列，现在鼠标移出其边界，允许重新调整
                    section_end_pos = self.sectionViewportPosition(self.index_cancelled) + self.table.columnWidth(column_index)
                    if self.moved_x > section_end_pos:
                        self.setSectionResizeMode(self.index_cancelled, QtWidgets.QHeaderView.Interactive)
                        self.move_cancelled = False

            if not self.move_cancelled: # 如果没有列达到最小宽度限制，则允许默认的拖动行为
                super().mouseMoveEvent(event)
        else:
            super().mouseMoveEvent(event)

    def mouseReleaseEvent(self, event):
        self.track_move = False
        super().mouseReleaseEvent(event)
        # 释放鼠标后，将所有列的调整模式恢复为交互式
        for column_index in range(self.total_columns):
            self.setSectionResizeMode(column_index, QtWidgets.QHeaderView.Interactive)

class Run_me:
    def __init__(self):
        self.app = QtWidgets.QApplication(sys.argv)
        self.Dialog = QtWidgets.QDialog()
        self.ui = Ui_Dialog()
        self.ui.setupUi(self.Dialog)
        self.Dialog.show()

        # 调整列宽以获取初始最小宽度
        self.ui.tableWidget.resizeColumnsToContents()
        self.columns_min_width = self.find_table_column_min_width()

        # 创建并设置自定义表头
        custom_header = CustomHeader(self.ui.tableWidget, self.columns_min_width)
        self.ui.tableWidget.setHorizontalHeader(custom_header)
        self.ui.tableWidget.updateGeometries() # 更新几何布局以确保显示

        sys.exit(self.app.exec_())

    def find_table_column_min_width(self):
        """获取当前所有列的宽度作为最小宽度限制"""
        total_columns = self.ui.tableWidget.columnCount()
        min_widths = []
        for column_index in range(total_columns):
            column_width = self.ui.tableWidget.columnWidth(column_index)
            min_widths.append(column_width)
        return min_widths

if __name__ == "__main__":
    program = Run_me()