用pyqt写一个通过鼠标滚动放大缩小图片的代码

A：

from PyQt5.QtWidgets import QApplication, QWidget, QLabel
from PyQt5.QtGui import QPixmap
from PyQt5.QtCore import Qt

class ImageWidget(QWidget):
    def __init__(self, image_path):
        super().__init__()

        # 设置窗口大小
        self.setGeometry(100, 100, 500, 500)

        # 创建标签对象
        self.image_label = QLabel(self)

        # 加载图片
        self.image_pixmap = QPixmap(image_path)

        # 设置图片标签大小和位置
        self.image_label.setGeometry(0, 0, self.width(), self.height())
        self.image_label.setPixmap(self.image_pixmap)

        # 开启滚轮事件监听
        self.setMouseTracking(True)

    def wheelEvent(self, event):
        # 获取当前图片大小
        width = self.image_pixmap.width()
        height = self.image_pixmap.height()

        # 计算缩放比例
        delta = event.angleDelta().y() / 120
        scale = 1 + delta * 0.1

        # 重新设置图片大小
        new_width = int(width * scale)
        new_height = int(height * scale)
        self.image_pixmap = self.image_pixmap.scaled(new_width, new_height, Qt.KeepAspectRatio)

        # 更新图片标签和窗口大小
        self.image_label.setPixmap(self.image_pixmap)
        self.resize(new_width, new_height)

if __name__ == '__main__':
    import sys
    app = QApplication(sys.argv)
    window = ImageWidget('image.jpg')
    window.show()
    sys.exit(app.exec_())

注：该程序实现了图片的放大和缩小功能，只需将 `image.jpg` 替换为你自己的图片路径即可。