QComboBox

常用方法

addItem()	添加一个下拉选项
addItems()	从列表中添加下拉选项
Clear()	删除下拉选项集合中的所有选项
count()	返回下拉选项集合中的数目
currentText()	返回选中选项的文本
itemText(i)	获取索引为i的item的选项文本
currentIndex()	返回选中项的索引
setltemText(int  index,text)	改变序号为index项的文本

常用信号

Activated	当用户选中一个下拉选项时发射该信号
currentIndexChanged	当下拉选项的索引发生改变时发射该信号
highlighted	当选中一个已经选中的下拉选项时，发射该信号

代码示例

import sys
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *class ComboxDemo(QWidget):def __init__(self, parent=None):super(ComboxDemo, self).__init__(parent)self.setWindowTitle("combox 例子")self.resize(300, 90)layout = QVBoxLayout()self.lbl = QLabel("")self.cb = QComboBox()self.cb.addItem("C")self.cb.addItem("C++")self.cb.addItems(["Java", "C#", "Python"])self.cb.currentIndexChanged.connect(self.selectionchange)layout.addWidget(self.cb)layout.addWidget(self.lbl)self.setLayout(layout)def selectionchange(self, i):self.lbl.setText(self.cb.currentText())self.lbl.adjustSize()print("Items in the list are :")for count in range(self.cb.count()):print('item' + str(count) + '=' + self.cb.itemText(count))print("Current index", i, "selection changed ", self.cb.currentText())if __name__ == '__main__':app = QApplication(sys.argv)comboxDemo = ComboxDemo()comboxDemo.show()sys.exit(app.exec_())