python - 使 QGraphisItem 适合 View

Question

是一种适合 View 中任何图像(我在 QPixmap 中导入)并保持宽高比的方法>。我尝试了很多解决方案，但没有一个有效。 我也不确定我需要适应什么？ QGraphicsView 中的 QGraphicsScene？或者 QGraphicsView 中的 QPixmap？

from PyQt5 import QtCore, QtGui, QtWidgets


class GraphicsView(QtWidgets.QGraphicsView):
    def __init__(self, parent=None):
        super(GraphicsView, self).__init__(parent)

        scene = QtWidgets.QGraphicsScene()
        self.setScene(scene)




if __name__ == "__main__":
    import sys

    app = QtWidgets.QApplication(sys.argv)
    w = GraphicsView()
    photo = QtGui.QPixmap("image.jpg")
    w.scene().addPixmap(photo)
    w.resize(640, 480)
    w.show()
    sys.exit(app.exec_())

Answer 1

你必须在QGraphicsView的resizeEvent()方法中使用QGraphicsView的fitInView()方法:

from PyQt5 import QtCore, QtGui, QtWidgets


class GraphicsView(QtWidgets.QGraphicsView):
    def __init__(self, parent=None):
        super(GraphicsView, self).__init__(parent)
        scene = QtWidgets.QGraphicsScene(self)
        self.setScene(scene)
        self.m_pixmap_item = self.scene().addPixmap(QtGui.QPixmap())

    def setPixmap(self, pixmap):
        self.m_pixmap_item.setPixmap(pixmap)

    def resizeEvent(self, event):
        if not self.m_pixmap_item.pixmap().isNull():
            self.fitInView(self.m_pixmap_item, QtCore.Qt.KeepAspectRatio)
        super(GraphicsView, self).resizeEvent(event)


if __name__ == "__main__":
    import sys

    app = QtWidgets.QApplication(sys.argv)
    w = GraphicsView()
    photo = QtGui.QPixmap("image.jpg")
    w.setPixmap(photo)
    w.resize(640, 480)
    w.show()
    sys.exit(app.exec_())