python - QRectF 没有出现在我的 QGraphicsScene 中

Question

我正在尝试使用 QGraphicsView(在 Maya 中)并获得一些代码，我将在下面粘贴这些代码。问题是带有 QGraphicsView 的窗口出现了，但看起来 QGraphicsScene(带有我的 QRectF)没有出现。我仍然对继承的工作方式感到困惑，所以有人可以指出我哪里做错了。谢谢。

from PySide2 import QtGui, QtCore, QtWidgets
from shiboken2 import wrapInstance
import maya.OpenMaya as om
import maya.OpenMayaUI as omui
import maya.cmds as cmds
import os, functools


def getMayaWindow():
    pointer = omui.MQtUtil.mainWindow()
    if pointer is not None:
        return wrapInstance(long(pointer), QtWidgets.QWidget)


class testUi(QtWidgets.QDialog):
    def __init__(self, parent=None):  
        if parent is None:
            parent = getMayaWindow()
        super(testUi, self).__init__(parent) 
        self.window = 'vl_test'
        self.title = 'Test Remastered'
        self.size = (1000, 650)

        self.create() 

    def create(self):
        if cmds.window(self.window, exists=True):
            cmds.deleteUI(self.window, window=True)

        self.setWindowTitle(self.title)
        self.resize(QtCore.QSize(*self.size))
        self.testik = test(self)  

        self.mainLayout = QtWidgets.QVBoxLayout() 
        self.mainLayout.addWidget(self.testik)
        self.setLayout(self.mainLayout) 


class test(QtWidgets.QGraphicsView):

    def __init__(self, parent=None):
        super(test, self).__init__(parent) 

        self._scene = QtWidgets.QGraphicsScene() 
        rect_item = QtWidgets.QGraphicsRectItem(QtCore.QRectF(0, 0, 100, 100))
        rect_item.setFlag(QtWidgets.QGraphicsItem.ItemIsMovable, True)
        self._scene.addItem(rect_item) 

v = testUi()
v.show()

Answer 1

问题是您还没有将 QGraphicsScene 添加到 QGraphicsView:

class test(QtWidgets.QGraphicsView):
    def __init__(self, parent=None):
        super(test, self).__init__(parent) 
        self._scene = QtWidgets.QGraphicsScene() 
        self.setScene(self._scene) # <---
        rect_item = QtWidgets.QGraphicsRectItem(QtCore.QRectF(0, 0, 100, 100))
        rect_item.setFlag(QtWidgets.QGraphicsItem.ItemIsMovable, True)
        self._scene.addItem(rect_item)