pyqt5教程QGraphicsScene及QGraphicsView使用基础

from PyQt5.QtCore import Qt, QRectF
from PyQt5.QtGui import QColor, QPen, QBrush, QFont
from PyQt5.QtWidgets import (QGraphicsView, QGraphicsScene, QApplication)
class MainWindow(QGraphicsView):
 def __init__(self, parent=None):
  super(MainWindow, self).__init__(parent)
  # 创建场景
  self.scene = MyGraphScene(self)
  # 在场景中添加文字
  self.addPoint(0, 0, "p1")
  self.addPoint(50, 100, "p2")
  self.addPoint(100, 0, "p3")
  self.setSceneRect(QRectF(-150, -150, 400, 400))
  self.scale(2, 2)
  # 将场景加载到窗口
  self.setScene(self.scene)
 def addPoint(self, x, y, name):
  self.scene.addEllipse(x, y, 16, 16, QPen(QColor(Qt.red)), QBrush(QColor(Qt.red)))
  text = self.scene.addText(name)
  text.setDefaultTextColor(QColor(Qt.red))
  text.setFont(QFont("Courier New", 16))
  text.setPos(x, y - 30)
class MyGraphScene(QGraphicsScene):
 def __init__(self, parent=None):
  super(MyGraphScene, self).__init__(parent)
 def drawBackground(self, painter, rect):
 	# 在这里可以绘制底板，比如网格
  pass
if __name__ == '__main__':
 import sys
 # 每个PyQt程序必须创建一个application对象，sys.argv 参数是命令行中的一组参数
 # 注意：application在 PyQt5.QtWidgets 模块中
 # 注意：application在 PyQt4.QtGui 模块中
 app = QApplication(sys.argv)
 # 创建桌面窗口
 mainWindow = MainWindow()
 # 显示桌面窗口
 mainWindow.show()
 sys.exit(app.exec_())