1. 从本地加载图片

img = QImage("/Users/admin/Desktop/hello.png")
pimg = QPixmap.fromImage(image)
self.imgLabel.setPixmap(pimg)

2. 图片铺满QLabel

img = QImage("/Users/admin/Desktop/hello.png")
pimg = QPixmap.fromImage(image)
self.imgLabel.setPixmap(pimg)
self.imgLabel.setScaledContents(True)

3. 等比例显示未知大小的图片

img = QImage("/Users/admin/Desktop/hello.png")
pimg = QPixmap.fromImage(image)

fw = self.imgLabel.width() / width
fh = self.imgLabel.height() / height

factor = min(fw, fh)

width = int(width * factor)
height = int(height * factor)
nimg = img.scaled(width, height, QtCore.Qt.KeepAspectRatio, QtCore.Qt.SmoothTransformation)
self.imgLabel.setPixmap(nimg)