当 QGraphicsView 画一条超出其大小时的线时，如何使它的大小增加？

Question

我有这个屏幕：

我在上面画了一条线，从板子里出来：

#!/usr/bin/python
# -*- coding: utf-8 -*-

import sys
from PyQt4 import QtGui, QtCore

class Example(QtGui.QWidget):

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

    def initUI(self):
        self.drawingPanel = DrawingPanel(self)

        verticalLayout = QtGui.QVBoxLayout( self )
        verticalLayout.addWidget(self.drawingPanel)

        self.setLayout( verticalLayout )
        # self.setGeometry(300, 300, 400, 300)
        self.resize( 400, 300 )

        self.setWindowTitle('Review')
        self.show()


class DrawingPanel(QtGui.QGraphicsView):

    def __init__(self, parent):
        QtGui.QGraphicsView.__init__(self, parent)
        self.setScene(QtGui.QGraphicsScene(self))
        self.setSceneRect(QtCore.QRectF(self.viewport().rect()))

        # self.setSizePolicy(QtGui.QSizePolicy.Maximum, QtGui.QSizePolicy.Maximum)

        pencil = QtGui.QPen(QtCore.Qt.black, 2, QtCore.Qt.SolidLine)
        pencil.setStyle(QtCore.Qt.DotLine)

        self.scene().addLine(QtCore.QLineF(0, 0, 300, 600), pencil)


def main():

    app = QtGui.QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())


if __name__ == '__main__':
    main()

如何让面板产生滚动条并且能够显示整条画好的线？

我可以找到一些其他问题：

QGraphicsView / QGraphicsScene size matching
QGraphicsView / QGraphicsScene image size

Answer 1

我修复了它只是从代码中删除了这一行：

self.setSceneRect(QtCore.QRectF(self.viewport().rect()))

#!/usr/bin/python
# -*- coding: utf-8 -*-

import sys
from PyQt4 import QtGui, QtCore

class Example(QtGui.QWidget):

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

    def initUI(self):
        self.drawingPanel = DrawingPanel(self)

        verticalLayout = QtGui.QVBoxLayout( self )
        verticalLayout.addWidget( self.drawingPanel )

        self.setLayout( verticalLayout )
        # self.setGeometry( 300, 300, 400, 300 )
        self.resize( 400, 300 )

        self.setWindowTitle('Review')
        self.show()


class DrawingPanel(QtGui.QGraphicsView):

    def __init__( self, parent ):
        super( DrawingPanel, self ).__init__( parent )

        scene = QtGui.QGraphicsScene()
        self.setScene( scene )

        # self.setSceneRect( QtCore.QRectF( self.viewport().rect() ) )
        # self.setSizePolicy( QtGui.QSizePolicy.Maximum, QtGui.QSizePolicy.Maximum )

        pencil = QtGui.QPen( QtCore.Qt.black, 2, QtCore.Qt.SolidLine )
        pencil.setStyle( QtCore.Qt.DotLine )

        self.scene().addLine( QtCore.QLineF(0, 0, 300, 600), pencil )


def main():

    app = QtGui.QApplication( sys.argv )
    ex = Example()
    sys.exit( app.exec_() )


if __name__ == '__main__':
    main()

当 QGraphicsView 画一条超出其大小时的线时，如何使它的大小增加？

How to make the QGraphicsView increase its size when it is draw a line beyond its size?

python

qt

pyqt4