from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_MainWindow(object):
   def setupUi(self, MainWindow):
       MainWindow.setObjectName("MainWindow")
       MainWindow.resize(800, 600)
       self.centralwidget = QtWidgets.QWidget(MainWindow)
       self.centralwidget.setObjectName("centralwidget")
       self.pushButton = QtWidgets.QPushButton(self.centralwidget)
       self.pushButton.setGeometry(QtCore.QRect(340, 430, 75, 23))
       self.pushButton.setObjectName("pushButton")
       self.pushButton_2 = QtWidgets.QPushButton(self.centralwidget)
       self.pushButton_2.setGeometry(QtCore.QRect(510, 430, 75, 23))
       self.pushButton_2.setObjectName("pushButton_2")
       self.textEdit = QtWidgets.QTextEdit(self.centralwidget)
       self.textEdit.setGeometry(QtCore.QRect(280, 200, 411, 161))
       self.textEdit.setObjectName("textEdit")
       self.lineEdit = QtWidgets.QLineEdit(self.centralwidget)
       self.lineEdit.setGeometry(QtCore.QRect(210, 90, 113, 20))
       self.lineEdit.setObjectName("lineEdit")
       self.lineEdit_2 = QtWidgets.QLineEdit(self.centralwidget)
       self.lineEdit_2.setGeometry(QtCore.QRect(410, 90, 113, 20))
       self.lineEdit_2.setObjectName("lineEdit_2")
       self.label = QtWidgets.QLabel(self.centralwidget)
       self.label.setGeometry(QtCore.QRect(80, 90, 54, 12))
       self.label.setObjectName("label")
       self.pushButton_3 = QtWidgets.QPushButton(self.centralwidget)
       self.pushButton_3.setGeometry(QtCore.QRect(600, 100, 75, 23))
       self.pushButton_3.setObjectName("pushButton_3")
       self.lineEdit_3 = QtWidgets.QLineEdit(self.centralwidget)
       self.lineEdit_3.setGeometry(QtCore.QRect(190, 430, 113, 20))
       self.lineEdit_3.setObjectName("lineEdit_3")
       MainWindow.setCentralWidget(self.centralwidget)
       self.menubar = QtWidgets.QMenuBar(MainWindow)
       self.menubar.setGeometry(QtCore.QRect(0, 0, 800, 23))
       self.menubar.setObjectName("menubar")
       MainWindow.setMenuBar(self.menubar)
       self.statusbar = QtWidgets.QStatusBar(MainWindow)
       self.statusbar.setObjectName("statusbar")
       MainWindow.setStatusBar(self.statusbar)

       self.retranslateUi(MainWindow)
       QtCore.QMetaObject.connectSlotsByName(MainWindow)

   def retranslateUi(self, MainWindow):
       _translate = QtCore.QCoreApplication.translate
       MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
       self.pushButton.setText(_translate("MainWindow", "发送"))
       self.pushButton_2.setText(_translate("MainWindow", "关闭"))
       self.label.setText(_translate("MainWindow", "服务器"))
       self.pushButton_3.setText(_translate("MainWindow", "连接"))
import sys
from PyQt5 import QtWidgets
import untitled
import   socket
class Mywindow(QtWidgets.QMainWindow, untitled.Ui_MainWindow):
   quest=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
   def __init__(self):
       super(Mywindow, self).__init__()
       self.setupUi(self)  #继承于Ui_MainWindow
       self.pushButton_3.clicked.connect(self.lianjie)
       self.pushButton.clicked.connect(self.xiaoxi)
   def  lianjie(self):
       self.quest.connect((self.lineEdit.Text(),int(self.lineEdit_2.Text())))
   def  xiaoxi(self):
       self.quest.send(self.lineEdit_3.Text().encode())
       a=self.quest.recv(100).decode()
       self.textEdit.setText(a)
       self.quest.close()
if __name__ == "__main__":
   app = QtWidgets.QApplication(sys.argv)
   window = Mywindow()
   window.show()
   sys.exit(app.exec_())

上面是客户机代码 ，代码和PYQT5联系在一起了

下面是服务器代码,没有和窗体联系在一起

import   socket
service=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
service.bind(('127.0.0.1',6))
service.listen(3)
tao,add=service.accept()
data=tao.recv(100).decode()
tao.send(data.encode())
tao.close()
service.close()

为什么我打开客户机，连接按钮 ，系统退出，产生错误呢？