如何在pyqt中捕获鼠标在QTableWidget项的事件？

Question

当我将鼠标悬停在我的QTableWidget项目上时,我想要做的是更改QTableWidget项目的颜色.

Answer 1

首先,表格小部件需要打开鼠标跟踪才能获得悬停事件.

其次,我们需要找到一些信号告诉我们什么时候鼠标进入和离开表格单元格,以便可以在正确的时间更改背景颜色.

QTableWidget类具有cellEntered/itemEntered信号,但鼠标离开单元格时没有任何内容.因此,我们需要创建一些自定义信号来做到这一点.

TableWidget下面演示脚本中的类设置了必要的cellExited/ itemExited信号,然后显示了当鼠标悬停时如何连接所有内容以更改项目背景:

from PyQt4 import QtGui, QtCore

class TableWidget(QtGui.QTableWidget):
    cellExited = QtCore.pyqtSignal(int, int)
    itemExited = QtCore.pyqtSignal(QtGui.QTableWidgetItem)

    def __init__(self, rows, columns, parent=None):
        QtGui.QTableWidget.__init__(self, rows, columns, parent)
        self._last_index = QtCore.QPersistentModelIndex()
        self.viewport().installEventFilter(self)

    def eventFilter(self, widget, event):
        if widget is self.viewport():
            index = self._last_index
            if event.type() == QtCore.QEvent.MouseMove:
                index = self.indexAt(event.pos())
            elif event.type() == QtCore.QEvent.Leave:
                index = QtCore.QModelIndex()
            if index != self._last_index:
                row = self._last_index.row()
                column = self._last_index.column()
                item = self.item(row, column)
                if item is not None:
                    self.itemExited.emit(item)
                self.cellExited.emit(row, column)
                self._last_index = QtCore.QPersistentModelIndex(index)
        return QtGui.QTableWidget.eventFilter(self, widget, event)

class Window(QtGui.QWidget):
    def __init__(self, rows, columns):
        QtGui.QWidget.__init__(self)
        self.table = TableWidget(rows, columns, self)
        for column in range(columns):
            for row in range(rows):
                item = QtGui.QTableWidgetItem('Text%d' % row)
                self.table.setItem(row, column, item)
        layout = QtGui.QVBoxLayout(self)
        layout.addWidget(self.table)
        self.table.setMouseTracking(True)
        self.table.itemEntered.connect(self.handleItemEntered)
        self.table.itemExited.connect(self.handleItemExited)

    def handleItemEntered(self, item):
        item.setBackground(QtGui.QColor('moccasin'))

    def handleItemExited(self, item):
        item.setBackground(QtGui.QTableWidgetItem().background())

if __name__ == '__main__':

    import sys
    app = QtGui.QApplication(sys.argv)
    window = Window(6, 3)
    window.setGeometry(500, 300, 350, 250)
    window.show()
    sys.exit(app.exec_())