使用QPainter在PyQt标签中删除鼠标释放后的矩形

from PyQt5.QtWidgets import QApplication, QMainWindow, QLabel
from PyQt5.QtGui import QPainter, QColor, QPen
from PyQt5.QtCore import Qt, QRect

class CustomLabel(QLabel):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.rect = QRect()  # 用于存储矩形的坐标和尺寸

    def mousePressEvent(self, event):
        self.rect.setTopLeft(event.pos())  # 记录鼠标按下时的位置

    def mouseReleaseEvent(self, event):
        self.rect.setBottomRight(event.pos())  # 记录鼠标释放时的位置
        self.update()  # 更新标签的绘制

    def paintEvent(self, event):
        super().paintEvent(event)
        painter = QPainter(self)
        painter.setPen(QPen(Qt.red, 2, Qt.SolidLine))
        painter.drawRect(self.rect)  # 绘制矩形

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.setWindowTitle("Delete Rectangle Example")
        self.setGeometry(100, 100, 400, 300)

        label = CustomLabel(self)
        label.setGeometry(50, 50, 300, 200)

        self.setCentralWidget(label)

if __name__ == "__main__":
    app = QApplication([])
    window = MainWindow()
    window.show()
    app.exec_()