import sys
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
class spindemo(QWidget):
    def __init__(self, parent=None):
  super(spindemo, self).__init__(parent)
  self.setWindowTitle("SpinBox 例子")
  self.resize(300, 100)
       
  layout = QVBoxLayout()
  self.l1=QLabel("current value:")
  self.l1.setAlignment(Qt.AlignCenter)
  layout.addWidget(self.l1)
  self.sp = QSpinBox()
  layout.addWidget(self.sp)
  self.sp.valueChanged.connect(self.valuechange)
  self.setLayout(layout)
       
    def valuechange(self):  
  self.l1.setText("current value:" + str(self.sp.value()) )
if __name__ == '__main__':
    app = QApplication(sys.argv)
    ex = spindemo()
    ex.show()
    sys.exit(app.exec_())