Pyqt5 QTreeWidget CurrentItemChanged信号发送整数作为前一项

Question

我有一个QTreeWidget项和信号CurrentItemChanged连接到一个基于数据库查找更新GUI的方法。在

CurrentItemChanged文档说它将把QTreeWidgetItems作为参数传递给该方法。首先是当前项目，然后是先前选定的项目。在

我看到一个QTreeWidgetItem后跟一个整数，很可能是当前所选项的列，而被传递。这种行为似乎不是任何人的Pyqt5文档的一部分。在

在我自己存储对前一项的引用之前，我是否遗漏了一些内容？代码简单得令人沮丧：

^{1}$

Answer 1

This signal is emitted when the current item changes. The current item is specified by current, and this replaces the previous current item.

试试看：

import sys
from PyQt5 import QtWidgets, QtGui, QtCore

class Window(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super(Window, self).__init__(parent)
        self.vlayout = QtWidgets.QVBoxLayout()

        # tree widget item
        tree_widget_item = QtWidgets.QTreeWidgetItem(['Item 1'])
        tree_widget_item.addChild(QtWidgets.QTreeWidgetItem(['Sub item 1']))  
        tree_widget_item.addChild(QtWidgets.QTreeWidgetItem(['Sub item 2']))

        # tree widget
        tree_widget = QtWidgets.QTreeWidget(self)
        tree_widget.addTopLevelItem(tree_widget_item)
        self.vlayout.addWidget(tree_widget)

        tree_widget.currentItemChanged.connect(self.current_item_changed)

    @QtCore.pyqtSlot(QtWidgets.QTreeWidgetItem, QtWidgets.QTreeWidgetItem)
    def current_item_changed(self, current, previous):
        print('\ncurrent: {}, \nprevious: {}'.format(current, previous))


application = QtWidgets.QApplication(sys.argv)
window = Window()
window.setWindowTitle('Tree widget')
window.resize(250, 180)
window.show()
sys.exit(application.exec_())