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)
        # 創(chuàng)建場景
        self.scene = MyGraphScene(self)
        # 在場景中添加文字
        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)
        # 將場景加載到窗口
        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):
    	# 在這里可以繪制底板，比如網(wǎng)格
        pass
if __name__ == '__main__':
    import sys
    # 每個PyQt程序必須創(chuàng)建一個application對象，sys.argv 參數(shù)是命令行中的一組參數(shù)
    # 注意：application在 PyQt5.QtWidgets 模塊中
    # 注意：application在 PyQt4.QtGui 模塊中
    app = QApplication(sys.argv)
    # 創(chuàng)建桌面窗口
    mainWindow = MainWindow()
    # 顯示桌面窗口
    mainWindow.show()
    sys.exit(app.exec_())