023-QObject-信号的操作-API

柔光的暖阳◎ 2023-07-07 08:40 55阅读 0赞

资源：[Python-GUI-PyQ5总概述.xmind][Python-GUI-PyQ5_.xmind]；[QObject.xmind][]

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**一、destroyed(obj):对象呗销毁时，发射此信号（其中widget.信号.connect(槽)：连接信号与槽）**

from PyQt5.Qt import *
    class Window(QWidget):
        def __init__(self):
            super().__init__()
            self.setWindowTitle("QObject的学习")  # 窗口标题
            self.resize(500, 500)  # 设置窗口大小
            self.setup_ui()
    
        def setup_ui(self):
            self.QObject信号的操作()
    
        def QObject信号的操作(self):
            self.obj=QObject()  #self是指Window,不会被释放
    
            def destroy_cao(obj):   #监听obj2对象被释放
                print("obj2对象被释放了",obj)
            self.obj.destroyed.connect(destroy_cao)  #这里并没有打印"obj2对象被释放了 <PyQt5.QtCore.QObject object at 0x00000204E0F7D310>"
    
            del self.obj  #这里打印"obj2对象被释放了 <PyQt5.QtCore.QObject object at 0x00000204E0F7D310>"
    
    if __name__ == '__main__':
        import sys
        app = QApplication(sys.argv)
        window = Window()
        window.show()
        sys.exit(app.exec_())

--------------------

**二、obj.objectNameChanged(objectName):对象名称改变时发射此信号**

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**三、obj.disconnect()：取消连接信号与槽。**

obj:控件-->取消控件的所有信号连接，信号-->取消指定信号的连接

from PyQt5.Qt import *
    class Window(QWidget):
        def __init__(self):
            super().__init__()
            self.setWindowTitle("QObject的学习")  # 窗口标题
            self.resize(500, 500)  # 设置窗口大小
            self.setup_ui()
    
        def setup_ui(self):
            self.QObject信号的操作()
    
        def QObject信号的操作(self):
            self.obj=QObject()
            def obj_name_cao(name):
                print("对象名称发生了改变",name)
    
            self.obj.objectNameChanged.connect(obj_name_cao)
            self.obj.setObjectName("666")
            self.obj.objectNameChanged.disconnect(obj_name_cao)  #虽然信号被触发，但是信号与槽的关系断开
            self.obj.setObjectName("888")
    
    if __name__ == '__main__':
        import sys
        app = QApplication(sys.argv)
        window = Window()
        window.show()
        sys.exit(app.exec_())
    
    #返回
    '''
    对象名称发生了改变 666
    '''

--------------------

**四、widget.blockSignals(bool)：临时（取消）指定控件所有的信号与槽的连接**

from PyQt5.Qt import *
    class Window(QWidget):
        def __init__(self):
            super().__init__()
            self.setWindowTitle("QObject的学习")  # 窗口标题
            self.resize(500, 500)  # 设置窗口大小
            self.setup_ui()
    
        def setup_ui(self):
            self.QObject信号的操作()
    
        def QObject信号的操作(self):
            self.obj=QObject()
            def obj_name_cao(name):
                print("对象名称发生了改变",name)
    
            self.obj.objectNameChanged.connect(obj_name_cao)
            self.obj.setObjectName("666")
            self.obj.blockSignals(True)  #临时阻断
            self.obj.setObjectName("888")
            self.obj.blockSignals(False)
            self.obj.setObjectName("777")
    
    if __name__ == '__main__':
        import sys
        app = QApplication(sys.argv)
        window = Window()
        window.show()
        sys.exit(app.exec_())
    
    #返回
    '''
    对象名称发生了改变 666
    对象名称发生了改变 777
    '''

--------------------

**五、widget.signalsBlocked()：信号是否被阻止**

from PyQt5.Qt import *
    class Window(QWidget):
        def __init__(self):
            super().__init__()
            self.setWindowTitle("QObject的学习")  # 窗口标题
            self.resize(500, 500)  # 设置窗口大小
            self.setup_ui()
    
        def setup_ui(self):
            self.QObject信号的操作()
    
        def QObject信号的操作(self):
            self.obj=QObject()
            def obj_name_cao(name):
                print("对象名称发生了改变",name)
    
            self.obj.objectNameChanged.connect(obj_name_cao)
            self.obj.setObjectName("666")
            print(self.obj.signalsBlocked(),"1")
    
            self.obj.blockSignals(True)  #临时阻断
            print(self.obj.signalsBlocked(),"2")
            self.obj.setObjectName("888")
    
            self.obj.blockSignals(False)  #回复连接
            print(self.obj.signalsBlocked(),"3")
            self.obj.setObjectName("777")
    
    if __name__ == '__main__':
        import sys
        app = QApplication(sys.argv)
        window = Window()
        window.show()
        sys.exit(app.exec_())
    
    #返回
    '''
    对象名称发生了改变 666
    False 1
    True 2
    False 3
    对象名称发生了改变 777
    '''

--------------------

**六、widget.receivers(信号)：返回连接到信号的接收器数量**

from PyQt5.Qt import *
    class Window(QWidget):
        def __init__(self):
            super().__init__()
            self.setWindowTitle("QObject的学习")  # 窗口标题
            self.resize(500, 500)  # 设置窗口大小
            self.setup_ui()
    
        def setup_ui(self):
            self.QObject信号的操作()
    
        def QObject信号的操作(self):
            self.obj=QObject()
            def obj_name_cao(name):
                print("对象名称发生改变1",name)
    
            def obj_name_cao2(name):
                print("对象名称发生改变2",name)
    
            self.obj.objectNameChanged.connect(obj_name_cao)
            self.obj.objectNameChanged.connect(obj_name_cao2)
    
            print(self.obj.receivers(self.obj.objectNameCAhanged))
    
            self.obj.setObjectName("666")
    
    if __name__ == '__main__':
        import sys
        app = QApplication(sys.argv)
        window = Window()
        window.show()
        sys.exit(app.exec_())
    
    #返回
    '''
    2
    对象名称发生改变1 666
    对象名称发生改变2 666
    '''

[Python-GUI-PyQ5_.xmind]: https://download.csdn.net/download/qq_40078031/12138844
[QObject.xmind]: https://download.csdn.net/download/qq_40078031/12151862