5.信号与槽_js 信号槽-优快云博客

博客主要介绍了QObject信号与槽的相关操作，包括建立连接、取消连接、临时取消连接，还提到可通过obj.receivers(信号名)返回连接到信号的接收器数量，最后给出了两个相关案例。

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QObject信号与槽建立连接

def QObjectSignal(self):
    self.obj = QObject()
    
    def destroyed_slot(obj):
        print('对象被释放了'， obj)
    
    self.obj.destroyed.connect(destroyed_slot)
    del self.obj

def QObjectSignal(self):
    self.obj = QObject()
    
    def changed_slot(name):
        print('对象被改名了'， name)
    
    self.obj.objNameChanged.connect(changed_slot)
    self.obj.setObjectName('abc')

QObject信号与槽取消连接

def QObjectSignal(self):
    self.obj = QObject()
    
    def changed_slot(name):
        print('对象被改名了'， name)
    
    self.obj.objNameChanged.connect(changed_slot)
    self.obj.setObjectName('abc')
    
    self.obj.objNameChanged.disconnect()
    self.obj.setObjectName('aaa')

# 不会输出abc

QObject信号与槽临时取消连接

def QObjectSignal(self):
    self.obj = QObject()
    
    def changed_slot(name):
        print('对象被改名了'， name)
    
    self.obj.objNameChanged.connect(changed_slot)
    self.obj.blockSignals(True)
    self.obj.setObjectName('abc')
    self.obj.blockSignals(False)
    self.obj.setObjectName('aaa')

# 输出：aaa

obj.receivers(信号名) 返回连接到信号的接收器数量

def QObjectSignal(self):
    self.obj = QObject()
    
    def changed_slot(name):
        print('对象被改名了'， name)
    
    self.obj.objNameChanged.connect(changed_slot)
    
    self.obj.receivers(self.obj.objNameChanged)    # 返回连接到信号的接收器数量，此处为 1

案例1

btn = QPushbutton(self)
btn.setText('click')
def clicked_slot():
    print('被点击了')

btn.clicked.connect(clicked_slot)

案例2

# 方法1
def changed_slot(title):
    print('标题被修改了'， title)
    window.windowTitleChanged.disconnect()
    window.setWindowTitle('abc-' + title)
    window.windowTitleChanged.connect(changed_slot)


window.windowTitleChanged.connect(changed_slot)
window.setWindowTitle('hello')

window.setWindowTitle('hello111')



# 方法2
def changed_slot(title):
    print('标题被修改了'， title)
    window.blockSignals(True)
    window.setWindowTitle('abc-' + title)
    window.blockSignals(False)

window.windowTitleChanged.connect(changed_slot)
window.setWindowTitle('hello')

window.setWindowTitle('hello111')