成功解决：Could not install packages due to an OSError:

错误：

ERROR:

Could not install packages due to an OSError: [Errno 2] No such file or directory: 'C:\Users\XIAODA~1\AppData\Local\Temp\pip-install-yeyhod79\opencv-contribpython_fbfb96aba52e4ff583caa3d0730309d1\opencv/samples/winrt_universal/VideoCaptureXAML/video_capture_xaml/video_capturxaml.WindowsPhone/video_capture_xaml.WindowsPhone_TemporaryKey.pfx'

截图

原因：因为Python Page模块文件的文件路径太长，如果超过了260个字符这文件不能被创建成功。所以需要解决Windows中对长文件名的限制问题。通过修改注册表中 HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem 的LongPathsEnabled 值由0改为1