PyQt5 QTableWidget 单元格合并：解决多选与重叠合并问题

import sys
from PyQt5.QtCore import Qt, QEvent
from PyQt5.QtWidgets import QApplication, QMainWindow, QTableWidget, QVBoxLayout, QWidget, QPushButton, QMessageBox


class ExcelLikeTable(QMainWindow):
    def __init__(self):
        super().__init__()

        self.mergeButton = None
        self.unmergeButton = None
        self.tableWidget = QTableWidget()
        self.initUI()

    def initUI(self):
        self.setWindowTitle("Excel-like Table with PyQt5")
        self.setGeometry(100, 100, 800, 600)

        self.tableWidget.setColumnCount(10)
        self.tableWidget.setHorizontalHeaderLabels([f'Column {chr(65+i)}' for i in range(10)])
        self.tableWidget.setRowCount(10) # 增加初始行数以便测试

        # 填充一些示例数据
        for r in range(10):
            for c in range(10):
                self.tableWidget.setItem(r, c, QTableWidgetItem(f"Cell {chr(65+c)}{r+1}"))

        self.tableWidget.clearSelection()
        # 确保选择模式允许连续选择项目
        self.tableWidget.setSelectionMode(QTableWidget.ContiguousSelection)
        self.tableWidget.setSelectionBehavior(QTableWidget.SelectItems)

        self.mergeButton = QPushButton("Merge Cells")
        self.unmergeButton = QPushButton("Unmerge Cells")
        self.mergeButton.clicked.connect(self.mergeCells)
        self.unmergeButton.clicked.connect(self.unmergeCells)

        layout = QVBoxLayout()
        layout.addWidget(self.tableWidget)
        layout.addWidget(self.mergeButton)
        layout.addWidget(self.unmergeButton)

        centralWidget = QWidget()
        centralWidget.setLayout(layout)
        self.setCentralWidget(centralWidget)

        self.tableWidget.installEventFilter(self)

    def mergeCells(self):
        # 使用 selectedIndexes() 获取所有选中单元格的索引
        selection = self.tableWidget.selectedIndexes()

        if not selection:
            QMessageBox.information(self, "提示", "请选择要合并的单元格。")
            return

        if len(selection) == 1:
            QMessageBox.information(self, "提示", "只选中了一个单元格，无需合并。")
            return

        # 在合并新区域前，先清除选中单元格可能存在的旧合并状态
        # 这一步非常关键，可以避免复杂的嵌套或重叠合并问题
        for index in selection:
            row, column = index.row(), index.column()
            # 检查当前单元格是否是某个合并区域的起始点
            if (self.tableWidget.rowSpan(row, column) > 1 or
                self.tableWidget.columnSpan(row, column) > 1):
                # 如果是，将其跨度重置为1x1，即取消该单元格的合并状态
                self.tableWidget.setSpan(row, column, 1, 1)

        # 清除跨度操作可能会影响当前的 selection，所以重新获取并排序
        # 排序确保索引按行、列顺序排列，便于确定合并区域的边界
        selection = sorted(self.tableWidget.selectedIndexes())

        # 确定合并区域的边界
        topRow = selection[0].row()
        leftColumn = selection[0].column()
        bottomRow = selection[-1].row()
        rightColumn = selection[-1].column()

        # 检查选择是否是连续的矩形区域
        # 遍历所有选中索引，确保它们都在由 topRow, leftColumn, bottomRow, rightColumn 
        # 定义的矩形区域内，并且该区域内的所有单元格都被选中。
        # 这一步是为了防止用户选择非连续的单元格进行合并
        expected_cells = set()
        for r in range(topRow, bottomRow + 1):
            for c in range(leftColumn, rightColumn + 1):
                expected_cells.add((r, c))

        actual_cells = set()
        for index in selection:
            actual_cells.add((index.row(), index.column()))

        if expected_cells != actual_cells:
            QMessageBox.warning(self, "警告", "请选择一个连续的矩形区域进行合并。")
            return

        rowCount = bottomRow - topRow + 1
        columnCount = rightColumn - leftColumn + 1

        # 执行合并操作
        self.tableWidget.setSpan(topRow, leftColumn, rowCount, columnCount)
        QMessageBox.information(self, "成功", f"单元格已合并：从 ({topRow+1}, {chr(65+leftColumn)}) 到 ({bottomRow+1}, {chr(65+rightColumn)})")


    def unmergeCells(self):
        # QTableWidget 提供了 clearSpans() 方法，可以一次性清除所有单元格的合并状态
        self.tableWidget.clearSpans()
        QMessageBox.information(self, "成功", "所有单元格合并已取消。")

    def addRow(self):
        rowCount = self.tableWidget.rowCount()
        self.tableWidget.insertRow(rowCount)

    def eventFilter(self, source, event):
        if event.type() == QEvent.KeyPress and event.key() == Qt.Key_Return:
            currentRow = self.tableWidget.currentRow()
            currentColumn = self.tableWidget.currentColumn()
            if currentRow == self.tableWidget.rowCount() - 1:
                self.addRow()
            self.tableWidget.setCurrentCell(currentRow + 1, currentColumn)
            return True
        return super(ExcelLikeTable, self).eventFilter(source, event)

    # 调试方法，用于打印单元格跨度信息
    def debugPrintCellSpans(self):
        print("Debugging cell spans:")
        for i in range(self.tableWidget.rowCount()):
            for j in range(self.tableWidget.columnCount()):
                rowSpan = self.tableWidget.rowSpan(i, j)
                colSpan = self.tableWidget.columnSpan(i, j)
                if rowSpan > 1 or colSpan > 1:
                    print(f"Cell at ({i+1}, {chr(65+j)}) has row span: {rowSpan}, column span: {colSpan}")

if __name__ == '__main__':
    app = QApplication(sys.argv)
    ex = ExcelLikeTable()
    ex.show()
    sys.exit(app.exec_())

class ExcelLikeTable(QMainWindow):
    # ... (其他代码保持不变)

    def unmergeCells(self):
        # QTableWidget 提供了 clearSpans() 方法，可以一次性清除所有单元格的合并状态
        self.tableWidget.clearSpans()
        QMessageBox.information(self, "成功", "所有单元格合并已取消。")

    # ... (其他代码保持不变)