Qtablewidget 中单元格上的 MouseMove 事件以显示或打印消息

Posted 2023-03-30

【中文标题】Qtablewidget 中单元格上的 MouseMove 事件以显示或打印消息

【英文标题】：MouseMove event on cell in Qtablewidget to display or print a message

【发布时间】：2019-01-01 23:25:50

【问题描述】：

我有 QTablewidget，我想在特定单元格B 上使用 mousemoveevent。当鼠标移到这个单元格B 上时，会出现或打印一条消息。我已经创建了构造函数，但它确实不起作用。从这些代码行中可以期待一切。

def mouseMoveEvent(self, event):
    it = self.item(self.rowCount(),1) 
    it.QToolTip.showText('Insert')
    self.onHovered()

请记住，当单击单元格并工作时，会分配 Qtooltip。但我想通过 MouseMoveevent 做到这一点。也许我的 MouseEvent 代码构造函数不正确。

期待表现。

import sys
from PyQt5 import QtCore, QtGui, QtWidgets


def copy_widget(w):
    if isinstance(w, QtWidgets.QWidget):
        new_w = type(w)()
        if isinstance(w, QtWidgets.QComboBox):
            vals = [w.itemText(ix) for ix in range(w.count())]
            new_w.addItems(vals)
        return new_w

class LoadTable(QtWidgets.QTableWidget):
    def __init__(self, parent=None):
        super(LoadTable, self).__init__(1, 5, parent)
        self.setFont(QtGui.QFont("Helvetica", 10, QtGui.QFont.Normal, italic=False))   
        headertitle = ("A","B","C","D","E")
        self.setHorizontalHeaderLabels(headertitle)
        self.verticalHeader().hide()
        self.horizontalHeader().setHighlightSections(False)
        self.horizontalHeader().setSectionResizeMode(QtWidgets.QHeaderView.Fixed)

        self.setSelectionMode(QtWidgets.QAbstractItemView.NoSelection)
        self.setColumnWidth(0, 130)

        combox_lay = QtWidgets.QComboBox(self)
        combox_lay.addItems(["I","II"])
        self.setCellWidget(0, 4, combox_lay)

        self.cellChanged.connect(self._cellclicked)


    @QtCore.pyqtSlot(int, int)
    def _cellclicked(self, r, c):
        it = self.item(r, c)
        it.setTextAlignment(QtCore.Qt.AlignCenter)
        n_it = self.item(r,1)
        n_it.setToolTip('Test') 


    @QtCore.pyqtSlot()
    def _addrow(self):
        rowcount = self.rowCount()
        self.insertRow(rowcount)
        combox_add = QtWidgets.QComboBox(self)
        combox_add.addItems(["I","II"])
        self.setCellWidget(rowcount, 4, combox_add)

    @QtCore.pyqtSlot()
    def _removerow(self):
        if self.rowCount() > 0:
            self.removeRow(self.rowCount()-1)

    @QtCore.pyqtSlot()
    def _copyrow(self):
        r = self.currentRow()
        if 0 <= r < self.rowCount():
            cells = "items": [], "widgets": []
            for i in range(self.columnCount()):
                it = self.item(r, i)
                if it:
                    cells["items"].append((i, it.clone()))
                w = self.cellWidget(r, i)
                if w:
                    cells["widgets"].append((i, copy_widget(w)))
            self.copy(cells, r+1)

    def copy(self, cells, r):
        self.insertRow(r)
        for i, it in cells["items"]:
            self.setItem(r, i, it)
        for i, w in cells["widgets"]:
            self.setCellWidget(r, i, w)

    def mouseMoveEvent(self, event):
        it = self.item(self.rowCount(),1)
        it.QToolTip.showText('Insert')
        self.onHovered()

    def onHovered(self):
        print("Works")


class ThirdTabLoads(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super(ThirdTabLoads, self).__init__(parent)    

        table = LoadTable()

        add_button = QtWidgets.QPushButton("Add")
        add_button.clicked.connect(table._addrow)

        delete_button = QtWidgets.QPushButton("Delete")
        delete_button.clicked.connect(table._removerow)

        copy_button = QtWidgets.QPushButton("Copy")
        copy_button.clicked.connect(table._copyrow)

        button_layout = QtWidgets.QVBoxLayout()
        button_layout.addWidget(add_button, alignment=QtCore.Qt.AlignBottom)
        button_layout.addWidget(delete_button, alignment=QtCore.Qt.AlignTop)
        button_layout.addWidget(copy_button, alignment=QtCore.Qt.AlignTop)

        tablehbox = QtWidgets.QHBoxLayout()
        tablehbox.setContentsMargins(10, 10, 10, 10)
        tablehbox.addWidget(table)

        grid = QtWidgets.QGridLayout(self)
        grid.addLayout(button_layout, 0, 1)
        grid.addLayout(tablehbox, 0, 0)        


if __name__ == '__main__':
    app = QtWidgets.QApplication(sys.argv)
    w = ThirdTabLoads()
    w.show()
    sys.exit(app.exec_())

【问题讨论】：

那么鼠标经过单元格A还是必须发生的单元格C？

如果鼠标通过单元格 A 而其余的期望来自单元格 B 必须什么都不做。这就是为什么我只标记it = self.item(self.rowCount(),1)。

只有在单元格 B 中才应该显示工具提示？

没错，根据pyqt5文档推荐使用Qtooltips show text，因为反应和显示更快

【参考方案1】：

必须使用 itemEntered 信号，但要做到这一点，除了 item 之外还必须启用 mouseTracking。添加一行时，并不意味着每个框的项目都存在，因此我对其进行了修改以创建它。

class LoadTable(QtWidgets.QTableWidget):
    def __init__(self, parent=None):
        super(LoadTable, self).__init__(0, 5, parent)
        self.setFont(QtGui.QFont("Helvetica", 10, QtGui.QFont.Normal, italic=False))   
        headertitle = ("A","B","C","D","E")
        self.setHorizontalHeaderLabels(headertitle)
        self.verticalHeader().hide()
        self.horizontalHeader().setHighlightSections(False)
        self.horizontalHeader().setSectionResizeMode(QtWidgets.QHeaderView.Fixed)
        self.setSelectionMode(QtWidgets.QAbstractItemView.NoSelection)
        self.setColumnWidth(0, 130)

        self.setMouseTracking(True)
        self.itemEntered.connect(self.on_itemEntered)
        self._addrow()

    def on_itemEntered(self, it):
        QtWidgets.QToolTip.hideText()
        if it.column() == 1:
            r = self.visualItemRect(it)
            p = self.viewport().mapToGlobal(QtCore.QPoint(r.center().x(), r.top()))
            QtWidgets.QToolTip.showText(p, "Insert")

    @QtCore.pyqtSlot()
    def _addrow(self):
        rowcount = self.rowCount()
        self.insertRow(rowcount)
        combox_add = QtWidgets.QComboBox(self)
        combox_add.addItems(["I","II"])
        self.setCellWidget(rowcount, 4, combox_add)
        for c in range(self.columnCount()):
            self.setItem(rowcount, c, QtWidgets.QTableWidgetItem())
    # ...