报错AttributeError: 'QWidget' object has no attribute 'setCentralWidget'如何解决

[nllalt]

# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'sign.ui'
#
# Created: Sun Nov 13 17:09:05 2016
# by: PyQt4 UI code generator 4.11.3
#
# WARNING! All changes made in this file will be lost!

import sys
from PyQt4 import QtCore, QtGui

try:
_fromUtf8 = QtCore.QString.fromUtf8
except AttributeError:
def _fromUtf8(s):
return s

try:
_encoding = QtGui.QApplication.UnicodeUTF8
def _translate(context, text, disambig):
return QtGui.QApplication.translate(context, text, disambig, _encoding)
except AttributeError:
def _translate(context, text, disambig):
return QtGui.QApplication.translate(context, text, disambig)

class Ui_MainWindow(object):
def setupUi(self, MainWindow):
MainWindow.setObjectName(_fromUtf8("MainWindow"))
MainWindow.resize(747, 564)
self.centralwidget = QtGui.QWidget(MainWindow)
self.centralwidget.setObjectName(_fromUtf8("centralwidget"))
self.label = QtGui.QLabel(self.centralwidget)
self.label.setGeometry(QtCore.QRect(50, 30, 211, 61))
self.label.setStyleSheet(_fromUtf8("\n"
"font: 75 22pt \"Microsoft YaHei UI\";"))
self.label.setObjectName(_fromUtf8("label"))
self.label_2 = QtGui.QLabel(self.centralwidget)
self.label_2.setGeometry(QtCore.QRect(50, 120, 81, 18))
self.label_2.setStyleSheet(_fromUtf8("font: 9pt \"Microsoft YaHei UI\";"))
self.label_2.setObjectName(_fromUtf8("label_2"))
self.lineEdit = QtGui.QLineEdit(self.centralwidget)
self.lineEdit.setGeometry(QtCore.QRect(50, 150, 331, 25))
self.lineEdit.setObjectName(_fromUtf8("lineEdit"))
self.label_3 = QtGui.QLabel(self.centralwidget)
self.label_3.setGeometry(QtCore.QRect(50, 200, 81, 18))
self.label_3.setStyleSheet(_fromUtf8("font: 9pt \"Microsoft YaHei UI\";"))
self.label_3.setObjectName(_fromUtf8("label_3"))
self.lineEdit_2 = QtGui.QLineEdit(self.centralwidget)
self.lineEdit_2.setGeometry(QtCore.QRect(50, 230, 331, 25))
self.lineEdit_2.setObjectName(_fromUtf8("lineEdit_2"))
self.label_4 = QtGui.QLabel(self.centralwidget)
self.label_4.setGeometry(QtCore.QRect(50, 280, 81, 18))
self.label_4.setStyleSheet(_fromUtf8("font: 9pt \"Microsoft YaHei UI\";"))
self.label_4.setObjectName(_fromUtf8("label_4"))
self.lineEdit_3 = QtGui.QLineEdit(self.centralwidget)
self.lineEdit_3.setGeometry(QtCore.QRect(50, 310, 331, 25))
self.lineEdit_3.setObjectName(_fromUtf8("lineEdit_3"))
self.pushButton = QtGui.QPushButton(self.centralwidget)
self.pushButton.setGeometry(QtCore.QRect(50, 380, 112, 34))
self.pushButton.setStyleSheet(_fromUtf8("font: 9pt \"Microsoft YaHei UI\";\n"
"background-color: rgb(215, 215, 215);"))
self.pushButton.setObjectName(_fromUtf8("pushButton"))
MainWindow.setCentralWidget(self.centralwidget)
self.menubar = QtGui.QMenuBar(MainWindow)
self.menubar.setGeometry(QtCore.QRect(0, 0, 747, 30))
self.menubar.setObjectName(_fromUtf8("menubar"))
MainWindow.setMenuBar(self.menubar)
self.statusbar = QtGui.QStatusBar(MainWindow)
self.statusbar.setObjectName(_fromUtf8("statusbar"))
MainWindow.setStatusBar(self.statusbar)

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

def retranslateUi(self, MainWindow):
MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow", None))
self.label.setText(_translate("MainWindow", "欢迎注册", None))
self.label_2.setText(_translate("MainWindow", "名字", None))
self.label_3.setText(_translate("MainWindow", "密码", None))
self.label_4.setText(_translate("MainWindow", "重复密码", None))
self.pushButton.setText(_translate("MainWindow", "注册", None))

if __name__ == "__main__":
app = QtGui.QApplication(sys.argv)
Form = QtGui.QWidget()
ui = Ui_MainWindow()
ui.setupUi(Form)
Form.show()
sys.exit(app.exec_())

Python菜鸟，想简单实现一个用户注册注册界面，还没有与数据库进行连接，运行时报错
Traceback (most recent call last):
File "D:/PyCharm 2016.2.3/example/Sign.py", line 88, in <module>
ui.setupUi(Form)
File "D:/PyCharm 2016.2.3/example/Sign.py", line 64, in setupUi
MainWindow.setCentralWidget(self.centralwidget)
AttributeError: 'QWidget' object has no attribute 'setCentralWidget'

求大神告知解决办法。

[sxqxcbl]

Form = QtGui.QWidget()这行换成 Form = QtGui.QMainWindow() 因为你在pyqt中创建的是MainWindow，不是Widget或者dialog