PyQtGraph 禁用鼠标滚轮，但不影响鼠标的其他功能

Question

我有一个 pyqtgraph.ViewBox 小部件，里面有一张图片。鼠标已启用，所以我可以 select 在图像上画一个矩形，它会被缩放。但是有一个不需要的功能，缩放也会发生在鼠标滚轮滚动上。

如何只禁用鼠标滚轮，而其余的保持原样？

from PyQt5.QtWidgets import QApplication, QMainWindow
import pyqtgraph as pg
import cv2


class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        pg.setConfigOption('imageAxisOrder', 'row-major')
        pg.setConfigOption('leftButtonPan', False)  # if False, then dragging the left mouse button draws a rectangle
    
        self.grid = pg.GraphicsLayoutWidget()
        self.top_left = self.grid.addViewBox(row=1, col=1)

        image = cv2.imread('/path/to/your/image.jpg', cv2.IMREAD_UNCHANGED)
        self.image_item = pg.ImageItem()
        self.image_item.setImage(image)
        self.top_left.addItem(self.image_item)

        self.setCentralWidget(self.grid)


def main():
    app = QApplication([])
    window = MainWindow()
    window.show()
    app.exec_()


if __name__ == '__main__':
    main()

Answer 1

您可以在 ViewBox 上安装事件过滤器并捕获鼠标滚轮事件，在本例中 QEvent.GraphicsSceneWheel。

from PyQt5.QtWidgets import QApplication, QMainWindow
from PyQt5.QtCore import QEvent
import pyqtgraph as pg
import cv2


class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        pg.setConfigOption('imageAxisOrder', 'row-major')
        pg.setConfigOption('leftButtonPan', False)  # if False, then dragging the left mouse button draws a rectangle
    
        self.grid = pg.GraphicsLayoutWidget()
        self.top_left = self.grid.addViewBox(row=1, col=1)
        self.top_left.installEventFilter(self)

        image = cv2.imread('/path/to/your/image.jpg', cv2.IMREAD_UNCHANGED)
        self.image_item = pg.ImageItem()
        self.image_item.setImage(image)
        self.top_left.addItem(self.image_item)

        self.setCentralWidget(self.grid)

    def eventFilter(self, watched, event):
        if event.type() == QEvent.GraphicsSceneWheel:
            return True
        return super().eventFilter(watched, event)

Answer 2

它比接受的答案简单得多。在 ViewBox 上使用 setMouseEnabled：

from PyQt5.QtWidgets import QApplication, QMainWindow
import pyqtgraph as pg
import cv2


class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        pg.setConfigOption('imageAxisOrder', 'row-major')
        pg.setConfigOption('leftButtonPan', False)  # if False, then dragging the left mouse button draws a rectangle

        self.grid = pg.GraphicsLayoutWidget()
        self.top_left = self.grid.addViewBox(row=1, col=1)
        self.top_left.setMouseEnabled(x=False, y=False)  # <--- Add this line

        image = cv2.imread('/path/to/your/image.jpg', cv2.IMREAD_UNCHANGED)
        self.image_item = pg.ImageItem()
        self.image_item.setImage(image)
        self.top_left.addItem(self.image_item)

        self.setCentralWidget(self.grid)


def main():
    app = QApplication([])
    window = MainWindow()
    window.show()
    app.exec_()


if __name__ == '__main__':
    main()