Qt实现显示svg图片，并可拖动鼠标旋转，新人做的效果不是很好。环境ubuntu16.04+Qt5.6.1，本人新测代码在WIN7+Qt环境下可用。-Qt display SVG pictures, and drag the mouse rotation, the new effect is not very good. Environment ubuntu16.04+Qt5.6.1, my new test code is available in the WIN7+Qt environmen