PyQt5学习记录(三):Emitting signals

Objects created from a QObject can emit signals. The following example shows how we to emit custom signals.

使用QObject创建的对象可以发出信号.下面你这个例子向我们展示了如何发出信号.

下面是源码:

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# @Time    : 2017/10/24 下午2:33
# @Author  : Aries
# @Site    : 
# @File    : 1024-01-Emitting signals.py
# @Software: PyCharm


import sys
from PyQt5.QtCore import pyqtSignal,QObject,Qt
from PyQt5.QtWidgets import QMainWindow,QApplication,QLabel


class Communicate(QObject):
    closeApp = pyqtSignal()

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

        self.initUI()


    def initUI(self):
        self.c = Communicate()
        self.c.closeApp.connect(self.close)

        title = QLabel('点击鼠标即可关闭程序')
        title.move(300,100)
        self.setCentralWidget(title)
        #title设置居中
        title.setAlignment(Qt.AlignCenter)


        self.setGeometry(300,300,290,150)
        self.setWindowTitle('Emitting signals')
        self.show()


    def mousePressEvent(self, QMouseEvent):
        self.c.closeApp.emit()


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

重点代码解读:

1. 我们创建了一个closeApp的信号.当鼠标被点击的时候,这个信号会被发出.这个信号和QMainWindow的close()方法相关联.

class Communicate(QObject):
    closeApp = pyqtSignal()   

#通过 Communicate()类创建一个信号,并且将这个信号与close()方法相关联
self.c = Communicate()
self.c.closeApp.connect(self.close) 

2.当鼠标被点击的时候,发出这个信号.我们重写了鼠标点击的方法,closeApp这个方法就会执行,程序就会关闭.

def mousePressEvent(self, event):
    
    self.c.closeApp.emit()

运行效果

image.png