pyqt5 qgraphicsView对象没有属性“resetmatrix”?

考虑这个Pyqt5例子,我们称之为 test.py (对我来说,在两种情况下都是一样的 python2 和 python3 在Ubuntu 18.04上):

#!/usr/bin/env python
from __future__ import print_function

import sys, os
from PyQt5 import QtCore, QtWidgets, QtGui

class PhotoViewer(QtWidgets.QGraphicsView):
    def __init__(self, parent):
        super(PhotoViewer, self).__init__(parent)
        self.parent = parent
        #self.resetMatrix() # SO: 39101834, but "AttributeError: 'PhotoViewer' object has no attribute 'resetMatrix'"
        self.scale(1.0, 1.0)

class MainWindow(QtWidgets.QMainWindow):
    def __init__(self):
        QtWidgets.QMainWindow.__init__(self)
        self.setWindowTitle("test.py")
        self.setMinimumWidth(1000)
        self.setMinimumHeight(600)
        self.viewer = PhotoViewer(self)
        wid = QtWidgets.QWidget(self)
        self.setCentralWidget(wid)
        VBlayout = QtWidgets.QVBoxLayout()
        VBlayout.addWidget(self.viewer)
        wid.setLayout(VBlayout)

if __name__ == "__main__":
    app = QtWidgets.QApplication([])
    main = MainWindow()
    main.show()
    sys.exit(app.exec_())

如果我按原样运行,它运行良好,没有问题。

如果我取消注释 self.resetMatrix() 行,则程序失败:

$ python test.py 
Traceback (most recent call last):
  File "test.py", line 29, in <module>
    main = MainWindow()
  File "test.py", line 20, in __init__
    self.viewer = PhotoViewer(self)
  File "test.py", line 11, in __init__
    self.resetMatrix() # SO: 39101834, but "AttributeError: 'PhotoViewer' object has no attribute 'resetMatrix'"
AttributeError: 'PhotoViewer' object has no attribute 'resetMatrix'

但我觉得这很奇怪,因为 PhotoViewer 继承自 QGraphicsView 呼唤 PhotoViewer.scale() 哪个是 QLogigsVIEW 方法显然不是问题-而且 How to reset the scale in QGraphicsView? 调用的文档 QGraphicsView()->resetMatrix() 应该是可能的,而且它也记录了以下两个方面:

• http://pyqt.sourceforge.net/Docs/PyQt4/qgraphicsview.html#resetMatrix
• http://pyqt.sourceforge.net/Docs/PyQt5/api/QtWidgets/qgraphicsview.html -可以找到C++文档。 here “-gt; https://doc.qt.io/qt-5/qgraphicsview.html#resetMatrix

我犯了什么错误-为什么我不能打电话 resetMatrix 在这种情况下,我应该怎么做才能调用这个函数呢?