PyQt5Day04--对象的父子关系+信号的操作

1.对象的父子关系

（1）API及内存管理机制

实际操作：

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_ceshi()
        self.QObject_对象的父子关系操作()

    def QObject_对象的父子关系操作(self):
        # **********测试API************开始
        # obj1=QObject()
        # obj2=QObject()
        # obj3=QObject()
        #
        # print('obj1',obj1)  # 0x0000028ED85CF1F8
        # print('obj2', obj2) # 0x0000028ED85CF0D8
        # print('obj3',obj3)  # 0x0000013E9DE6F168
        #
        # obj1.setParent(obj2)
        # obj3.setParent(obj2)
        # print(obj1.parent()) # 0x0000028ED85CF0D8
        # print(obj2.children()) # 两个
        # **********测试API************结束

        # ********内存管理机制**********开始
        obj1=QObject()
        obj2=QObject()

        obj2.setParent(obj1)

        # 开始监听obj2对象被释放
        obj2.destroyed.connect(lambda:print('obj2对象被释放了')) # obj2对象被释放了

        # *********内存管理机制*********结束


if __name__ == '__main__':
    import sys

    app=QApplication(sys.argv)
    window=Window()
    window.show()
    sys.exit(app.exec_())

（2）应用场景

（3）【案例】

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_ceshi()
        self.QObject_对象的父子关系操作()

    def QObject_对象的父子关系操作(self):
        # **********测试API************开始
        # obj1=QObject()
        # obj2=QObject()
        # obj3=QObject()
        #
        # print('obj1',obj1)  # 0x0000028ED85CF1F8
        # print('obj2', obj2) # 0x0000028ED85CF0D8
        # print('obj3',obj3)  # 0x0000013E9DE6F168
        #
        # obj1.setParent(obj2)
        # obj3.setParent(obj2)
        # print(obj1.parent()) # 0x0000028ED85CF0D8
        # print(obj2.children()) # 两个
        # **********测试API************结束

        # ********内存管理机制**********开始
        obj1=QObject()
        obj2=QObject()

        obj2.setParent(obj1)

        # 开始监听obj2对象被释放
        obj2.destroyed.connect(lambda:print('obj2对象被释放了')) # obj2对象被释放了

        # *********内存管理机制*********结束


if __name__ == '__main__':
    import sys

    app=QApplication(sys.argv)
    # window=Window()
    # window.show()

    # win1=QWidget()
    # win1.setWindowTitle("红色")
    # win1.setStyleSheet("background-color:red")
    # win1.show()
    #
    # win2=QWidget()
    # win2.setWindowTitle("绿色")
    # win2.setStyleSheet("background-color:green")
    # # win2.setParent(win1)
    # win2.resize(200,200)
    # win2.move(220,120)
    # win2.show()

    win_root=QWidget()

    label1=QLabel()
    label1.setText('label1')
    label1.setParent(win_root)
    label2 = QLabel()
    label2.move(50,50)
    label2.setText('label2')
    label2.setParent(win_root)

    btn=QPushButton(win_root)
    btn.move(100,100)
    btn.setText('btn')

    win_root.show()

    for sub_widget in win_root.findChildren(QLabel):
        print(sub_widget)
        sub_widget.setStyleSheet("background-color:green")

    sys.exit(app.exec_())

2、信号的操作

（1）API操作

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_信号的操作()

    def QObject_信号的操作(self):
        self.obj=QObject()
        **********测试API************开始
        obj=QObject()
        # obj.destroyed
        # obj.objNameChanged
        def destroy_cao():
            print("对象被释放了")
        obj.destroyed.connect(destroy_cao)

        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('XXX')
        print(self.obj.signalsBlocked(),'1')

        self.obj.blockSignals(True)  # 临时中断连接
        # self.obj.objectNameChanged.disconnect()
        self.obj.setObjectName('ooo')
        print(self.obj.signalsBlocked(), '2')

        self.obj.blockSignals(False)  # 恢复连接
        self.obj.setObjectName('hhhh')
        print(self.obj.signalsBlocked(), '3')
        **********测试API************结束

        ***********信号与槽按钮****************开始
        btn=QPushButton(self)
        btn.setText('点击我')

        def cao():
            print("点我做啥？")

        btn.clicked.connect(cao)

        ***********信号与槽按钮****************结束
        

if __name__ == '__main__':
    import sys
    window=Window()
    window.show()
    sys.exit(app.exec_())

（2）应用场景

（3）案例

from PyQt5.Qt import *

if __name__ == '__main__':
    import sys

    app=QApplication(sys.argv)
    window=QWidget()
    # 连接窗口标题变化的信号 与 槽
    def cao(title):
        print('窗口标题变化了',title)
        # window.windowTitleChanged.disconnect()
        window.blockSignals(True)
        window.setWindowTitle('撩课-'+title)
        window.blockSignals(False)
        #window.windowTitleChanged.connect(cao)

    window.windowTitleChanged.connect(cao)
    window.setWindowTitle("Hello Sz")
    window.setWindowTitle("Hello Sz2")

    window.show()
    sys.exit(app.exec_())

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时间：2020-03-02       20:55:52

作者：931935931（QQ）