擅长:python、mysql、java
<p>在实例化类时,如果不包含参数,就不能在<code>__init__</code>中包含参数。你知道吗</p>
<p>您必须:</p>
<pre class="lang-py prettyprint-override"><code>class View(QGraphicsView):
def __init__(self):
QGraphicsView.__init__(self, parent)
self.setScene(QGraphicsScene(self))
self.setSceneRect(QRectF(self.viewport().rect()))
def mousePressEvent(self, event):
if can_draw == 1 :
self._start = event.pos()
def mouseReleaseEvent(self, event):
if can_draw == 1:
start = QPointF(self.mapToScene(self._start))
end = QPointF(self.mapToScene(event.pos()))
self.scene().addItem(
QGraphicsLineItem(QLineF(start, end)))
</code></pre>
<p>然后你可以通过</p>
<pre class="lang-py prettyprint-override"><code>v = View()
</code></pre>
<p>然后你可以访问它的方法</p>