Qt / PyQt GraphicView

Question

我正在尝试使用qt designer重新创建一些pyqt代码。我使用pyuic4生成了一个简单的python代码。图像应仅在QgraphicView区域加载，但它覆盖了整个窗口，我看不到按钮。

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(608, 526)
        self.centralwidget = QtGui.QWidget(MainWindow)
        self.centralwidget.setObjectName(_fromUtf8("centralwidget"))
        self.widget = QtGui.QWidget(self.centralwidget)
        self.widget.setGeometry(QtCore.QRect(300, 20, 258, 244))
        self.widget.setObjectName(_fromUtf8("widget"))
        self.verticalLayout = QtGui.QVBoxLayout(self.widget)
        self.verticalLayout.setObjectName(_fromUtf8("verticalLayout"))
        self.graphicsView = QtGui.QGraphicsView(self.widget)
        self.graphicsView.setEnabled(True)
        self.graphicsView.setMinimumSize(QtCore.QSize(200, 200))
        self.graphicsView.setMaximumSize(QtCore.QSize(400, 400))
        self.graphicsView.setObjectName(_fromUtf8("graphicsView"))
        self.verticalLayout.addWidget(self.graphicsView)
        self.horizontalLayout = QtGui.QHBoxLayout()
        self.horizontalLayout.setObjectName(_fromUtf8("horizontalLayout"))
        self.pushButton = QtGui.QPushButton(self.widget)
        self.pushButton.setObjectName(_fromUtf8("pushButton"))
        self.horizontalLayout.addWidget(self.pushButton)
        self.pushButton_2 = QtGui.QPushButton(self.widget)
        self.pushButton_2.setObjectName(_fromUtf8("pushButton_2"))
        self.horizontalLayout.addWidget(self.pushButton_2)
        self.verticalLayout.addLayout(self.horizontalLayout)
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtGui.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 608, 22))
        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.pushButton.setText(_translate("MainWindow", "PushButton", None))
        self.pushButton_2.setText(_translate("MainWindow", "PushButton", None))

，主文件是：

import sys
from PyQt4 import QtCore, QtGui
from graphics_test_output import Ui_MainWindow

class Main(QtGui.QMainWindow,Ui_MainWindow):
    def __init__(self):
        super(Main,self).__init__()

        self.setupUi(self)
        self.mw = MainWidget()
        self.setCentralWidget(self.mw)

class MainWidget(QtGui.QWidget):
    def __init__(self, parent=None):
        super(MainWidget,self).__init__(parent)

        self.scene = QtGui.QGraphicsScene()
        self.view = QtGui.QGraphicsView(self.scene)
        layout = QtGui.QVBoxLayout()
        layout.addWidget(self.view)
        self.setLayout(layout)
        self.pixmap_item = QtGui.QGraphicsPixmapItem(QtGui.QPixmap('Image.png'), None, self.scene)


if __name__=='__main__':
    app = QtGui.QApplication(sys.argv)
    window = Main()
    window.show()
    sys.exit(app.exec_())

我添加了ui设计和当前输出的屏幕截图，它们会出现。

ui_design：

current_output：