我有一个QGraphicsscene,在QGraphicsView上有一张图片QPixmap。我决定使用QPixmap QGraphicsItem.ItemIsMovable。我想在移动时获得图片的位置。我该怎么做?
答案 0 :(得分:1)
如果您只是想知道当前的图片位置,可以从pixmapItem.pos()
或pixmapItem.x()
和pixmapItem.y()
收到。
但是如果你需要知道,当它被移动时,你可以继承QGraphicsPixmapItem
,设置QGraphicsItem.ItemSendsGeometryChanges
标志,并在覆盖的itemChange
函数中接收通知:
#!/usr/bin/env python
# -*- coding: utf-8 -*-
import sys
from PyQt4 import QtCore, QtGui
class MovablePixmapItem(QtGui.QGraphicsPixmapItem):
def __init__(self, pixmap, *args, **kwargs):
QtGui.QGraphicsPixmapItem.__init__(self, pixmap, *args, **kwargs)
self.setFlags(QtGui.QGraphicsItem.ItemIsMovable |
QtGui.QGraphicsItem.ItemSendsGeometryChanges)
def itemChange(self, change, value):
if change == QtGui.QGraphicsItem.ItemPositionHasChanged:
print value.toPointF()
# do other work, or emit signal
return QtGui.QGraphicsPixmapItem.itemChange(self, change, value)
class MainWidget(QtGui.QWidget):
def __init__(self, parent=None):
QtGui.QWidget.__init__(self, parent)
self.pixmapItem = MovablePixmapItem(QtGui.QPixmap('image.png'))
self.scene = QtGui.QGraphicsScene()
self.scene.addItem(self.pixmapItem)
self.view = QtGui.QGraphicsView(self.scene)
layout = QtGui.QVBoxLayout()
layout.addWidget(self.view)
self.setLayout(layout)
def do_test(self):
pass
if __name__ == "__main__":
app = QtGui.QApplication(sys.argv)
widget = MainWidget()
widget.resize(640, 480)
widget.show()
sys.exit(app.exec_())