pyqt5 绘制拓扑图

要在PyQt5中绘制拓扑图，可以使用QGraphicsView和QGraphicsScene类。QGraphicsView是一个用于显示QGraphicsScene的窗口部件，而QGraphicsScene是一个用于管理2D图形项的场景。以下是一个简单的示例代码，用于绘制一个简单的拓扑图：

from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
from PyQt5.QtGui import *
import sys

class Node(QGraphicsItem):
    def __init__(self, name):
        super().__init__()
        self.name = name
        self.edges = []

    def addEdge(self, edge):
        self.edges.append(edge)

    def boundingRect(self):
        return QRectF(-25, -25, 50, 50)

    def paint(self, painter, option, widget):
        painter.drawEllipse(-25, -25, 50, 50)
        painter.drawText(-10, 10, self.name)

class Edge(QGraphicsItem):
    def __init__(self, source, dest, weight=None):
        super().__init__()
        self.source = source
        self.dest = dest
        self.source.addEdge(self)
        self.dest.addEdge(self)
        self.weight = weight

    def boundingRect(self):
        return QRectF()

    def paint(self, painter, option, widget):
        painter.drawLine(self.source.pos(), self.dest.pos())
        if self.weight is not None:
            painter.drawText((self.source.pos() + self.dest.pos()) / 2, str(self.weight))

class Graph(QGraphicsScene):
    def __init__(self, adjacency_matrix):
        super().__init__()
        self.nodes = []
        self.edges = []
        for i in range(len(adjacency_matrix)):
            node = Node(str(i))
            self.addItem(node)
            node.setPos(100 * i, 100)
            self.nodes.append(node)
        for i in range(len(adjacency_matrix)):
            for j in range(i, len(adjacency_matrix)):
                if adjacency_matrix[i][j] != 0:
                    edge = Edge(self.nodes[i], self.nodes[j], adjacency_matrix[i][j])
                    self.addItem(edge)
                    self.edges.append(edge)

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.view = QGraphicsView(self)
        self.setCentralWidget(self.view)
        self.scene = Graph([[0, 1, 1, 0], [1, 0, 1, 1], [1, 1, 0, 1], [0, 1, 1, 0]])
        self.view.setScene(self.scene)

if __name__ == '__main__':
    app = QApplication(sys.argv)
    window = MainWindow()
    window.show()
    sys.exit(app.exec_())

该代码将绘制一个简单的无向图，其中节点用圆圈表示，边用线段表示。节点和边都是QGraphicsItem的子类，可以通过重写boundingRect()和paint()方法来自定义它们的外观。Graph类将邻接矩阵转换为节点和边，并将它们添加到QGraphicsScene中。MainWindow类创建一个QGraphicsView并将QGraphicsScene设置为其场景。运行该代码将显示一个简单的拓扑图。