在 PyQt 的菜单栏下方显示图像

Question

我有一个简单的流程：用户单击一个按钮，出现一个 QDialog 弹出窗口，我希望在 MenuBar 下方呈现一个菜单栏和一个图像（呈现发生在 paintEvent 期间）。

import sys

from PyQt5 import QtGui
from PyQt5.QtGui import QPixmap
from PyQt5.QtWidgets import QMainWindow, QApplication, QPushButton, QDialog, QMenuBar, QAction, QHBoxLayout


class Example(QMainWindow):
    def __init__(self):
        super().__init__()

        self.initUI()

    def initUI(self):
        self.button = QPushButton()
        self.button.setText("Click")
        self.button.setMaximumHeight(100)
        self.button.setMaximumWidth(100)
        self.button.clicked.connect(self.clicked)

        self.layout().addWidget(self.button)

        self.show()

    def clicked(self):
        self.something = SecondExample()
        self.something.exec()

class SecondExample(QDialog):
    def __init__(self):
        super().__init__()
        self.installEventFilter(self)

        layout = QHBoxLayout()

        toolbar = QMenuBar()
        toolbar.addAction(QAction("Edit", toolbar))
        toolbar.addAction(QAction("Polygon", toolbar))
        toolbar.addAction(QAction("Rectangle", toolbar))

        layout.setMenuBar(toolbar)

        self.setLayout(layout)

        self.pixmap = QPixmap(r"C:\Users\kjankosk\Desktop\Panasonic-OLED-TV-FZ950-Lifestyle.jpg")
        self.resize(self.pixmap.width(), self.pixmap.height())


    def paintEvent(self, event):
        super().paintEvent(event)

        painter = QtGui.QPainter(self)
        painter.setRenderHint(QtGui.QPainter.Antialiasing, True)

        painter.drawPixmap(self.rect(), self.pixmap)



if __name__ == '__main__':
    app = QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())

这是迄今为止我所拥有的可重现示例（编辑图像路径），但是图像的一部分出现在菜单栏后面。我该如何解决这个问题？我认为主要问题在于 rect() 调用，因为它似乎正在使用整个窗口，但我希望菜单栏会在“窗口外”。

Answer 1

一种可能的解决方案是提供一个类似于S.Nick 指示的偏移量，但正如您首先看到的缺点是计算取决于样式和操作系统的偏移量。所以另一种可能的解决方案是创建另一个显示图像的小部件并将其添加到布局中：

# ...
class Widget(QWidget):
    def __init__(self):
        super().__init__()

        self.pixmap = QPixmap(
            r"C:\Users\kjankosk\Desktop\Panasonic-OLED-TV-FZ950-Lifestyle.jpg"
        )

    def paintEvent(self, event):
        super().paintEvent(event)
        painter = QtGui.QPainter(self)
        painter.setRenderHint(QtGui.QPainter.Antialiasing, True)
        painter.drawPixmap(self.rect(), self.pixmap)

    def sizeHint(self):
        return self.pixmap.size()


class SecondExample(QDialog):
    def __init__(self):
        super().__init__()

        layout = QHBoxLayout(self)

        toolbar = QMenuBar()
        toolbar.addAction(QAction("Edit", toolbar))
        toolbar.addAction(QAction("Polygon", toolbar))
        toolbar.addAction(QAction("Rectangle", toolbar))

        layout.setMenuBar(toolbar)

        widget = Widget()
        layout.addWidget(widget)
# ...

Answer 2

试试看：

import sys
from PyQt5 import QtGui
from PyQt5.QtGui import QPixmap
from PyQt5.QtWidgets import (QMainWindow, QApplication, QPushButton, QDialog, 
                             QMenuBar, QAction, QHBoxLayout, QWidget, QGridLayout)

class SecondExample(QDialog):
    def __init__(self):
        super().__init__()
        self.installEventFilter(self)

        toolbar = QMenuBar()
        toolbar.addAction(QAction("Edit", toolbar))
        toolbar.addAction(QAction("Polygon", toolbar))
        toolbar.addAction(QAction("Rectangle", toolbar))

        layout = QHBoxLayout()
        layout.setMenuBar(toolbar)
        self.setLayout(layout)

        self.pixmap = QPixmap("D:/_Qt/__Qt/img/max1.jpg")      # py-qt.png
        self.resize(self.pixmap.width(), self.pixmap.height())

    def paintEvent(self, event):
        super().paintEvent(event)

        painter = QtGui.QPainter(self)
        painter.setRenderHint(QtGui.QPainter.Antialiasing, True)

#        painter.drawPixmap(self.rect(), self.pixmap)
        rect = self.rect().x(), self.rect().y()+20, self.rect().width(), self.rect().height()-20 # +++
        painter.drawPixmap(*rect, self.pixmap)                                                   # +++


class Example(QMainWindow):
    def __init__(self):
        super().__init__()

        self.initUI()

    def initUI(self):
        self.button = QPushButton(self)
        self.button.setText("Click")
        self.button.setMaximumHeight(100)
        self.button.setMaximumWidth(100)
        self.button.clicked.connect(self.clicked)

        centralWidget = QWidget()
        self.setCentralWidget(centralWidget)
        layout = QGridLayout(centralWidget)
#        self.layout().addWidget(self.button)
        layout.addWidget(self.button)

    def clicked(self):
        self.something = SecondExample()
        self.something.show()            # exec()

if __name__ == '__main__':
    app = QApplication(sys.argv)
    ex = Example()
    ex.show()
    sys.exit(app.exec_())