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from PyQt5.Qt import *

class Window(QWidget):

    def __init__(self):

        super().__init__()

        self.setWindowTitle("QObject的学习")

        self.resize(500, 500)

        self.setup_ui()

    def setup_ui(self):

        self.QObject类型判定()

    def QObject类型判定(self):

        # *************API***************开始

        obj = QObject()

        w = QWidget()

        btn = QPushButton()

        label = QLabel()

        objs = [obj, w, btn, label]

        for o in objs:

            print("是否是QWidget的控件类型",o.isWidgetType())

            print("父类是否是QWidget",o.inherits("QWidget"))

            print("父类是否是QPushButton",o.inherits("QPushButton"))

            print("------------------------------------------")

        # *************API***************结束

if __name__ == '__main__':

    import sys

    app = QApplication(sys.argv)

    window = Window()

    window.show()

    sys.exit(app.exec_())

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from PyQt5.Qt import *

class Window(QWidget):

    def __init__(self):

        super().__init__()

        self.setWindowTitle("QObject的学习")

        self.resize(500, 500)

        self.setup_ui()

    def setup_ui(self):

        self.QObject类型判定()

    def QObject类型判定(self):

        # *************API***************开始

        # obj = QObject()

        # w = QWidget()

        # btn = QPushButton()

        # label = QLabel()

        #

        # objs = [obj, w, btn, label]

        # for o in objs:

        #     print("是否是QWidget的控件类型",o.isWidgetType())

        #     print("父类是否是QWidget",o.inherits("QWidget"))

        #     print("父类是否是QPushButton",o.inherits("QPushButton"))

        #     print("------------------------------------------")

        # *************API***************结束

        # *************案例***************开始

        label1 = QLabel(self)

        label1.setText("景天科技苑")

        label1.move(100, 100)

        label2 = QLabel(self)

        label2.setText("科技不间断")

        label2.move(150, 150)

        btn = QPushButton(self)

        btn.setText("点我")

        btn.move(200, 200)

        #循环遍历子对象

        # for widget in self.findChildren(QLabel):

        for widget in self.children():

            # print(widget)

            # if widget.isWidgetType():

            #将子对象中为QLabel的对象设置背景样式

            if widget.inherits("QLabel"):

                widget.setStyleSheet("background-color: cyan;")

        # *************案例***************结束

if __name__ == '__main__':

    import sys

    app = QApplication(sys.argv)

    window = Window()

    window.show()

    sys.exit(app.exec_())

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from PyQt5.Qt import *

class Window(QWidget):

    def __init__(self):

        super().__init__()

        self.setWindowTitle("QObject的学习")

        self.resize(500, 500)

        self.setup_ui()

    def setup_ui(self):

        self.QObject对象删除()

    def QObject对象删除(self):

        obj1 = QObject()

        #为了防止局部变量运行完方法就销毁，将局部变量赋值给类变量

        self.obj1 = obj1

        obj2 = QObject()

        obj3 = QObject()

        obj3.setParent(obj2)

        obj2.setParent(obj1)

        #创建信号与槽

        obj1.destroyed.connect(lambda : print("obj1被释放了"))

        obj2.destroyed.connect(lambda : print("obj2被释放了"))

        obj3.destroyed.connect(lambda : print("obj3被释放了"))

        #删除对象

        # del obj2  #这样并不能删除

        obj2.deleteLater()

        print(obj1.children())

        #obj2并没有立马被释放

        print("obj2",obj2)

        #执行了deleteLater后，向主消息循环发送了一个event，下一次主消息循环收到这个event之后才会销毁对象，才会真正的去释放相关的对象

if __name__ == '__main__':

    import sys

    app = QApplication(sys.argv)

    window = Window()

    window.show()

    sys.exit(app.exec_())