Can not grab widget screen shot after set Samples

[WoodyWu]

Hi All,

Currently, I am working on an open GL project . After I set the samples for default QSurfaceFormat. I can't grab widget image, which is works fine before. I am using QOpenGLWidget rendering the graphics content. and use glew to replace Qt's own open GL wrapper. I tried grab and grabFramebuffer functionality, neither of them works. But they all works good if I don't set up anything about QSurfaceFormat's default samples. I don't know why.

Any solution about this?

Thank you!