python - 在小部件中嵌入 QGraphics

Question

我的窗口中有一个主小部件，其中包含很多小部件。如何在该小部件中插入 QGraphics View 和 QGraphicsScene？我还没有找到直接插入的方法，所以我尝试使用包装器，在本例中是盒子布局，但这不是一个好的解决方案。 QGraphicsScene 在布局限制中脱颖而出。

代码:

class UiVentana(QtWidgets.QMainWindow):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.setFixedSize(1500, 1015)

        widget_central = QtWidgets.QWidget(self)

        wrapper = QtWidgets.QHBoxLayout(widget_central)

        scene = QtWidgets.QGraphicsScene(wrapper)
        vista = QtWidgets.QGraphicsView(scene)

        wrapper.addWidget(vista)

        self.diedrico = Diedrico() # This is a class who draw things, not relevant
        self.diedrico.setFixedSize(2000, 2000)
        scene.addWidget(self.diedrico)
        self.setCentralWidget(widget_central)

我想得到这个结果:

from PyQt5 import QtCore, QtWidgets
from PyQt5.QtWidgets import QWidget
from PyQt5.QtCore import Qt
from PyQt5.QtGui import QPainter, QPen, QColor
import sys


class Diedrico(QWidget):
    def __init__(self, parent):
        super().__init__(parent)

    def paintEvent(self, event):
        qp = QPainter(self)
        qp.setPen(QPen(QColor(Qt.black), 5))
        qp.drawRect(500, 500, 1000, 1000)


class UiVentana(QtWidgets.QMainWindow):
    def __init__(self, parent=None):
        super(UiVentana, self).__init__(parent)
        self.resize(520, 520)
        self.widget_central = QtWidgets.QWidget(self)
        scrol = QtWidgets.QScrollArea(self.widget_central)
        scrol.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOn)
        scrol.setGeometry(QtCore.QRect(30, 30, 500, 500))
        scrol.setWidgetResizable(False)

        contenido = QtWidgets.QWidget()
        contenido.setGeometry(QtCore.QRect(0, 0, 2000, 2000))
        scrol.setWidget(contenido)

        self.Diedrico = Diedrico(contenido)
        self.Diedrico.setGeometry(QtCore.QRect(0, 0, 2000, 2000))
        self.setCentralWidget(self.widget_central)


if __name__ == "__main__":
    app = QtWidgets.QApplication(sys.argv)
    ui = UiVentana()
    ui.show()
    sys.exit(app.exec_())

但是使用 QGraphics 而不是滚动区域

Answer 1

使用窗口小部件创建的 QGraphicsProxyWidget 会考虑窗口小部件的最小尺寸来设置边界矩形，而 QGraphicsScene 使用边界矩形来设置初始场景矩形。

from PyQt5 import QtCore, QtGui, QtWidgets


class Diedrico(QtWidgets.QWidget):
    def paintEvent(self, event):
        qp = QtGui.QPainter(self)
        pen = QtGui.QPen(QtGui.QColor(QtCore.Qt.black), 5)
        qp.setPen(pen)
        qp.drawRect(500, 500, 1000, 1000)

    def minimumSizeHint(self):
        return QtCore.QSize(2000, 2000)


class UiVentana(QtWidgets.QMainWindow):
    def __init__(self, parent=None):
        super(UiVentana, self).__init__(parent)
        self.resize(520, 520)

        widget_central = QtWidgets.QWidget()
        self.setCentralWidget(widget_central)

        lay = QtWidgets.QVBoxLayout(widget_central)

        scene = QtWidgets.QGraphicsScene(self)
        view = QtWidgets.QGraphicsView(scene)

        diedrico = Diedrico()
        scene.addWidget(diedrico)

        lay.addWidget(view)


if __name__ == "__main__":
    import sys

    app = QtWidgets.QApplication(sys.argv)
    ui = UiVentana()
    ui.show()
    sys.exit(app.exec_())