提示信息：
QObject::moveToThread: Current thread (0x563e8bd48ed0) is not the object's thread (0x563e8ced9cf0).
Cannot move to target thread (0x563e8bd48ed0)
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "/home/zxq/anaconda3/envs/open3d/lib/python3.9/site-packages/cv2/qt/plugins" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
Available platform plugins are: xcb, eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, wayland-egl, wayland, wayland-xcomposite-egl, wayland-xcomposite-glx, webgl.错误信息中提到“"/home/zxq/anaconda3/envs/open3d/lib/python3.9/site-packages/cv2/qt/plugins”
解决办法1：首先按照提示信息的建议“Reinstalling the application may fix this problem.”，卸载原来的opencv，一般都能解决。
pip uninstall opencv-python opencv-contrib-python
// 安装新的opencv 下面这两个都行，最新版本不行。
pip install opencv-python==3.4.3.18 opencv-contrib-python==3.4.3.18
pip install opencv-python==4.0.0.21 opencv-contrib-python==4.0.0.21解决办法2：删除上面目录中的libqxcb.so文件即可
解决办法3：尝试过的另一种解决办法，卸载python3.9，安装python3.7