使用QSpinBox()构造计数器, 使用QSpinBox().valueChanged.connect() 来构造数值变化后的操作

QSpinBox.py 

"""
计数器控件(QSpinBox)
"""

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

class QSpinBoxDemo(QWidget):
    def __init__(self):
        super(QSpinBoxDemo, self).__init__()
        self.initUI()

    def initUI(self):
        self.setWindowTitle("QSpinBox演示")
        self.resize(300, 100)

        layout = QVBoxLayout()
        self.label = QLabel("当前值")
        self.label.setAlignment(Qt.AlignCenter)

        layout.addWidget(self.label)

        self.sb = QSpinBox()
        self.sb.setValue(18)
        self.sb.setRange(10, 38)
        self.sb.setSingleStep(3)
        layout.addWidget(self.sb)
        self.sb.valueChanged.connect(self.valueChange)

        self.setLayout(layout)

    def valueChange(self):
        self.label.setText('当前值' + str(self.sb.value()))


if __name__ == "__main__":
    app = QApplication(sys.argv)

    main = QSpinBoxDemo()
    main.show()

    sys.exit(app.exec_())