PyQt的signal 和 solit的补充

from PyQt5.QtWidgets import (QWidget
            , QVBoxLayout , QHBoxLayout,
             QLineEdit, QPushButton)

from PyQt5.QtCore import  pyqtSignal
from PyQt5 import QtCore
##############################################

# 参考大丸子的博客
#http://jimmykuu.sinaapp.com/blog/11

class LoginView(QWidget):

    ## 登录界面时发送 关闭信号
    quitSignal = pyqtSignal()
    loginSignal = pyqtSignal(list)
    # server端没有响应
    openFailureSignal = pyqtSignal()

    def __init__(self, parent=None):
        super(LoginView, self).__init__(parent)
        self.ids_receive = []

        self._init_ui()

    def _init_ui(self):    

        layout_button = QHBoxLayout()
        layout_input = QHBoxLayout()       

        self.input_name = QLineEdit()
        self.input_pass = QLineEdit()

        button_login =  QPushButton("登录")
        button_login.setObjectName("ok_button")

        button_quit  =  QPushButton("取消")
        button_hello  =  QPushButton("hello")
        self.button_hello = button_hello
        button_hello.setObjectName("hello_button")

        #button_login.clicked.connect(self.do_login)
        #button_quit.clicked.connect(self.loginQuit)

        layout_button.addWidget(button_login)
        layout_button.addWidget(button_quit)

        layout_input.addWidget(self.input_name)
        layout_input.addWidget(self.input_pass)
        layout_input.addWidget(self.button_hello)

        layout_main = QVBoxLayout()
        self.setLayout(layout_main)
        layout_main.addLayout(layout_button)
        layout_main.addLayout(layout_input)

        # QMetaObject. connectSlotsByName(QObject)
        #网上百度到的说明:其作用是如其名称一样，用来将QObject 里的子孙QObject的某些信号按照其objectName连接到相应的槽上
        #       ,如 button_hello.setObjectName("hello_button")
        # 官网解释用法: http://doc.qt.io/qt-5/qmetaobject.html#connectSlotsByName
        QtCore.QMetaObject.connectSlotsByName(self)

    def loginQuit(self):
        print ("cencel")

    #试试注销掉该装饰器
    # 有点奇怪啊，一旦注释掉装饰器,打印会执行两次啊
    #QtCore.pyqtSlot(str, str)可以携带参数的
    @QtCore.pyqtSlot()
    def on_hello_button_clicked(self):
        print('on_pbHello_clicked')

    @QtCore.pyqtSlot()
    def on_ok_button_clicked(self):
        print ("OK")
        self.loginSignal.emit([1, 2])

    def do_login(self):
        #获取用户和密码文本框的内容
        u_name = self.input_name.text()
        u_pass =  self.input_pass.text()

        print('u_name', u_name, u_pass)

if __name__ == '__main__':

    import sys
    from PyQt5.QtWidgets import QApplication
    app = QApplication(sys.argv)    

    login = LoginView()
    login.show()

    sys.exit(app.exec_())