如何从Qlistwidget中选择项目，并更新Pyqt5中的文本框？

通过Keyboard（按键事件）从QListWidget中选择项，效果很好。

但同时，我也想通过鼠标单击从QListWidget中选择Item。

尝试使用“ itemclicked.connect”，但它不符合我的预期。

我的代码在这里：

文件1（文件名：example_main_001.py）：

   import sys
    
    from PyQt5.QtWidgets import *
    from PyQt5.QtCore import  *
    from PyQt5.QtGui import *
    
    from example_source_file_001 import Sourcefile
    
    textbox_items = {
        "textbox1": ["Python", "Python 2.7", "Python 2.9", "Python 3.5", "Python 3.7", "National", "Zebra",
                     "Apple", "X Ray", "Boat", "Tiger", "Item001", "Item002", "Item003", "Item004", "Item005",
                     "001Item", "002Item", "003Item", "004Item", "005Item", "Ball", "Cat", "Dog", "Fish",
                     "Gold Fish", "Star Fish", "2821", "2822", "2823", "2811", "2812", "2813"],
    
        "textbox2": ["India","America","Russia","China","England","Iran","Iraq","Ice Land"],
    
        "textbox3": ["Red", "Dark red", "Light Red", "Redish Blue", "Redish Green", "Green","Blue","Dark 
 Blue", "Dark Green"]
        }
    
    
    class Mclick_sample_main(QWidget):
        def __init__(self):
            super().__init__()
    
            self.setWindowTitle("Mouse click Samples")
            self.textbox1 = QLineEdit()
            self.textbox2 = QLineEdit()
            self.textbox3 = QLineEdit()
            self.lbox1 = QListWidget()
            self.lbox2 = QListWidget()
    
            self.textbox1.setObjectName("textbox1")
            self.textbox2.setObjectName("textbox2")
            self.textbox3.setObjectName("textbox3")
            self.lbox1.setObjectName("listbox1")
            self.lbox2.setObjectName("listbox2")
    
            vbox = QVBoxLayout(self)
            vbox.addWidget(self.textbox1)
            vbox.addWidget(self.textbox2)
            vbox.addWidget(self.textbox3)
            vbox.addWidget(self.lbox2)
    
            self.current_textbox = None
            QApplication.instance().focusChanged.connect(self.on_focusChanged)
    
            self.textbox1.returnPressed.connect(lambda: self.textbox2.setFocus(Qt.ShortcutFocusReason))
            self.textbox2.returnPressed.connect(lambda: self.textbox3.setFocus(Qt.ShortcutFocusReason))
            self.textbox3.returnPressed.connect(lambda: self.textbox1.setFocus(Qt.ShortcutFocusReason))
    
        def on_focusChanged(self, old, new):
            fwidget = QApplication.focusWidget()
            if fwidget is not None:
    
                if isinstance(new, QLineEdit) and new != self.current_textbox:
                    self.current_textbox = new
                    self.lbox1.clear()
                    self.lbox1.addItems(textbox_items[new.objectName()])
                    self.lbox2.clear()
                    self.lbox2.addItems(textbox_items[new.objectName()])
    
                    self.getdetails_1 = Sourcefile(self.current_textbox, self.lbox1, self.lbox2)
                    self.current_textbox.textChanged.connect(self.getdetails_1.func_textbox_textchanged)
    
    def main():
        myapp = QApplication(sys.argv)
        mywin = Mclick_sample_main()
        mywin.show()
        sys.exit(myapp.exec_())
    
    
    if __name__ == "__main__":
        main()

文件2（文件名：example_source_file_001.py）

from PyQt5.QtWidgets import *
from PyQt5.QtGui import  *
from PyQt5.QtCore import *

flag = 1
search_text_length = 0
startitem_rowno = None
enditem_rowno = None
selected_item = None
selec_item = None


class Sourcefile(QWidget):
    def __init__(self, textbox, listbox1,listbox2,parent=None):
        super().__init__(listbox2)
        global startitem_rowno,enditem_rowno

        self.setFocusPolicy(Qt.StrongFocus)
        self.tbox1 = textbox
        self.lbox1 = listbox1
        self.lbox2 = listbox2

        self.tbox1.installEventFilter(self)
        self.lbox2.installEventFilter(self)

        startitem_rowno = 0
        enditem_rowno = len(self.lbox2) - 1



    def eventFilter(self, source, event):
        global cursor_position, textbox_value,selected_item


        if event.type() == QEvent.KeyPress and source is self.tbox1:

            if event.modifiers() == Qt.AltModifier and event.key() == Qt.Key_S:
                self.func_item_startswith()
                return True

            if event.key() == Qt.Key_Down:
                self.lbox2.setFocus()
                self.lbox2.setCurrentRow(startitem_rowno)
                cursor_position = self.tbox1.cursorPosition()
                textbox_value = self.tbox1.text()


            if event.key() == Qt.Key_Up:
                self.lbox2.setFocus()
                self.lbox2.setCurrentRow(enditem_rowno)
                cursor_position = self.tbox1.cursorPosition()
                textbox_value = self.tbox1.text()

            if event.key() == Qt.Key_Return:
                pass



        if event.type() == QEvent.KeyPress and source is self.lbox2:

            if event.key() == Qt.Key_Left or event.key() == Qt.Key_Backspace:
                self.tbox1.setFocus()
                return True

            elif event.key() == Qt.Key_Return :
                self.selected_item = self.lbox2.currentItem().text()

                if self.selected_item is not None:
                    self.tbox1.setText(self.selected_item)
                    self.tbox1.setFocus()
                    return True
            elif event.key() == Qt.Key_Up or event.key() == Qt.Key_Down:
                pass
        return super(Sourcefile, self).eventFilter(source, event)

    def func_item_startswith(self):

        global flag, startitem_rowno, enditem_rowno
        flag = 1
        startitem_rowno = 0
        enditem_rowno = startitem_count - 1
        # self.lbox2.clear()

        if startitem_count > 0:
            for item in item_startswith:
                self.lbox2.addItem(item.text())
        else:
            print("No Matching from start item")

    def func_item_normal(self):
        global falg,startitem_rowno,enditem_rowno
        flag = 0
        startitem_rowno = 0
        enditem_rowno = normal_count - 1

        self.lbox2.clear()

        if normal_count > 0:
            for item in item_normal:
                self.lbox2.addItem(item.text())

    def func_textbox_textchanged(self, txt):

        global search_text, search_text_length, total_listbox_item, availableitem_count, normal_count, startitem_count, \
            containitem_count, enditem_count, item_normal, item_startswith, item_contains, item_endswith, flag, \
            startitem_rowno, enditem_rowno

        search_text = self.tbox1.text()

        search_text_length = len(search_text)
        total_listbox_item = len(self.lbox2)

        item_normal = self.lbox1.findItems("*", Qt.MatchWildcard)
        item_startswith = self.lbox1.findItems(search_text, Qt.MatchStartsWith)

        normal_count = len(item_normal)
        startitem_count = len(item_startswith)

        self.func_item_normal()

        if search_text_length >= 1: pass
        else: flag = 1

        self.lbox2.clear()


        if flag == 1:

            self.func_item_startswith()
        else:
            self.func_item_normal()