PyQt5 signal and slot，pyqt5signal

PyQt5 signal and slot，pyqt5signal

PyQt5 的 signal 與 slot 有所改變，例如，先定義一個 ZeroSignal 類：

class ZeroSignal(QObject):    atzero = pyqtSignal(int)

使用時，一是綁定 slot 如下：

　　　　self.zerosig = ZeroSignal()       self.zerosig.atzero[int].connect(self.countZero)

然後是找個機會發動之：

def checkZero(self):        if self.value() == 0:            self.zerosig.atzero.emit(self.value())

大約如此，完整代碼如下：

import osimport sysfrom PyQt5.QtCore import *from PyQt5.QtGui import *from PyQt5.QtWidgets import *class ZeroSignal(QObject):    atzero = pyqtSignal(int)class ZeroSpinBox(QSpinBox):    def __init__(self, parent=None):        super(ZeroSpinBox, self).__init__(parent)        self.zeros = 0        self.valueChanged[int].connect(self.checkZero)        self.zerosig = ZeroSignal()        self.zerosig.atzero[int].connect(self.countZero)    def countZero(self, v):        if v == 0:            self.zeros += 1            print(self.zeros)    def checkZero(self):        if self.value() == 0:            self.zerosig.atzero.emit(self.value())            class Form(QDialog):    def __init__(self, parent=None):        super(Form, self).__init__(parent)                dial = QDial()        dial.setNotchesVisible(True)        spin = ZeroSpinBox()        layout = QHBoxLayout()        layout.addWidget(dial)        layout.addWidget(spin)        self.setLayout(layout)        dial.valueChanged.connect(spin.setValue)        spin.valueChanged.connect(dial.setValue)        spin.valueChanged.connect(self.emitZero)        self.setWindowTitle("Sinal and Solt")                self.zerobox = spin         self.zerobox.zerosig.atzero[int].connect(self.annouce)    def emitZero(self, v):        if v == 0:            self.zerobox.zerosig.atzero.emit(self.zerobox.zeros)    def annouce(self, v):        print("zero count: %d" % v)  # print two times because add ZeroSpinBox emit oncedef run():    app = QApplication(sys.argv)    form = Form()    form.show()    app.exec_()if __name__ == '__main__':    run()

OK！