如何在 PyQt 中的 QGraphicsView 旁边添加一个菜单栏（QMainWindow）？

Question

在 window 上显示带有滚动条的图片。我们可以借鉴它。我想向同一个 window 添加一个菜单栏。我尝试了以下，它没有用。当我运行 this.

时 window 上没有显示任何内容

#!/usr/bin/env python

from PyQt5.QtCore import (QLineF, QPointF, QRectF, Qt)
from PyQt5.QtGui import (QIcon, QBrush, QColor, QPainter, QPixmap)
from PyQt5.QtWidgets import (QAction, QMainWindow, QApplication, QGraphicsView, QGraphicsScene, QGraphicsItem,
                             QGridLayout, QVBoxLayout, QHBoxLayout,
                             QLabel, QLineEdit, QPushButton)

class TicTacToe(QGraphicsItem):
    def __init__(self):
        super(TicTacToe, self).__init__()

    def paint(self, painter, option, widget):
        painter.setPen(Qt.black)
        painter.drawLine(0,100,300,100)


    def boundingRect(self):
        return QRectF(0,0,300,300)

    def mousePressEvent(self, event):
        pos = event.pos()
        self.select(int(pos.x()/100), int(pos.y()/100))
        self.update()
        super(TicTacToe, self).mousePressEvent(event)

class MyGraphicsView(QGraphicsView):
    def __init__(self):
        super(MyGraphicsView, self).__init__()
        scene = QGraphicsScene(self)
        self.tic_tac_toe = TicTacToe()
        scene.addItem(self.tic_tac_toe)

        scene.addPixmap(QPixmap("exit.png"))

        self.setScene(scene)
        self.setCacheMode(QGraphicsView.CacheBackground)
        self.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOn)
        self.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOn)


    def keyPressEvent(self, event):
        key = event.key()
        if key == Qt.Key_R:
            self.tic_tac_toe.reset()
        super(MyGraphicsView, self).keyPressEvent(event)

class Example(QMainWindow):

    def __init__(self):
        super(Example, self).__init__()

        self.y = MyGraphicsView()

        self.initUI()


    def initUI(self):               

        menubar = self.menuBar()
        menu = menubar.addMenu('File')
        db_action = menu.addAction("Open file")

        self.setGeometry(30, 30, 30, 20)
        self.setWindowTitle('Menubar')    
        self.show()        


if __name__ == '__main__':
    import sys
    app = QApplication(sys.argv)
    mainWindow = Example()

    mainWindow.showFullScreen()
    sys.exit(app.exec_())

Answer 1

如果小部件是 window 的某个组件的子项，则它会显示在 window 中，在您的情况下 self.y 不是 Example 的子项, 但只是一个属性，一个可能的解决方案是将其设置为 centralWidget:

class Example(QMainWindow):

    def __init__(self):
        super(Example, self).__init__()

        self.y = MyGraphicsView()
        self.setCentralWidget(self.y)

        self.initUI()


    def initUI(self):               

        menubar = self.menuBar()
        menu = menubar.addMenu('File')
        db_action = menu.addAction("Open file")

        self.setGeometry(30, 30, 30, 20)
        self.setWindowTitle('Menubar')    
        self.show()

如何在 PyQt 中的 QGraphicsView 旁边添加一个菜单栏（QMainWindow）？

How to add a menubar(QMainWindow) alongside QGraphicsView in PyQt?

python

qt

pyqt

qgraphicsview

qmainwindow