pyqt5中，多层级自动补全选择

在PyQt5中，可以使用`QCompleter`类来实现自动补全功能。要实现多层级自动补全选择，可以考虑为每个层级创建一个`QCompleter`对象，并将前一个`QCompleter`对象作为后一个`QCompleter`对象的父对象。

下面是一个示例代码，其中第一个`QCompleter`对象用于自动补全省份，第二个`QCompleter`对象用于自动补全城市，第三个`QCompleter`对象用于自动补全区县：

import sys
from PyQt5.QtWidgets import QApplication, QLineEdit, QCompleter, QWidget, QVBoxLayout


class AutoCompleteLineEdit(QLineEdit):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.completers = []

    def addCompleter(self, completer):
        self.completers.append(completer)
        completer.setWidget(self)
        completer.activated.connect(self.onActivated)

    def onActivated(self, text):
        completer = self.sender()
        index = self.completers.index(completer)
        if index < len(self.completers) - 1:
            nextCompleter = self.completers[index + 1]
            nextCompleter.setCompletionPrefix(text)
            nextCompleter.complete()

class Example(QWidget):
    def __init__(self):
        super().__init__()

        provinces = ["北京", "上海", "天津", "重庆", "广东", "浙江", "江苏", "福建", "山东", "湖南", "湖北"]
        cities = ["北京市", "上海市", "天津市", "重庆市", "广州市", "深圳市", "杭州市", "南京市", "厦门市", "青岛市", "长沙市", "武汉市"]
        counties = ["东城区", "徐汇区", "和平区", "渝中区", "黄埔区", "拱墅区", "鼓楼区", "思明区", "市北区", "芙蓉区", "江汉区"]

        provinceCompleter = QCompleter(provinces)
        cityCompleter = QCompleter(cities)
        countyCompleter = QCompleter(counties)

        provinceLineEdit = AutoCompleteLineEdit()
        cityLineEdit = AutoCompleteLineEdit()
        countyLineEdit = QLineEdit()

        provinceLineEdit.addCompleter(provinceCompleter)
        cityLineEdit.addCompleter(cityCompleter)
        cityLineEdit.addCompleter(countyCompleter)

        layout = QVBoxLayout()
        layout.addWidget(provinceLineEdit)
        layout.addWidget(cityLineEdit)
        layout.addWidget(countyLineEdit)

        self.setLayout(layout)


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

在这个示例代码中，我们创建了一个名为`AutoCompleteLineEdit`的自定义控件，它继承自`QLineEdit`。该控件可以添加多个`QCompleter`对象，并将它们连接起来以实现多层级自动补全选择功能。

在`Example`类的构造函数中，我们创建了三个`QCompleter`对象，分别用于自动补全省份、城市和区县。接下来，我们创建了三个`QLineEdit`控件，并将它们添加到垂直布局中。然后，我们将省份自动补全`QCompleter`对象添加到省份`QLineEdit`控件中，并将城市自动补全`QCompleter`对象和区县自动补全`QCompleter`对象添加到城市`QLineEdit`控件中。最后，我们设置`Example`类的布局并显示窗口。