笔记本电脑摄像头使用dev_info=info.DeviceInfo，不显示摄像头参数，也无法调用摄像头，请问怎么解决？

Question

info=imaqhwinfo('winvideo')
No devices were detected for the 'winvideo' adaptor. For troubleshooting device detection issues, click here.

info =

包含以下字段的 struct:

   AdaptorDllName: 'C:\ProgramData\MATLAB\SupportPackages\R2019a\toolbox\imaq\supportpackages\genericvideo\adaptor\win64\mwwinvideoimaq.dll'
AdaptorDllVersion: '6.0 (R2019a)'
      AdaptorName: 'winvideo'
        DeviceIDs: {1×0 cell}
       DeviceInfo: [1×0 struct]

dev_info=info.DeviceInfo

dev_info =

包含以下字段的空的 1×0 struct 数组:

DefaultFormat
DeviceFileSupported
DeviceName
DeviceID
VideoInputConstructor
VideoDeviceConstructor
SupportedFormats

vid = videoinput('winvideo',1);
preview(vid);
frame = getsnapshot(vid);
figure;
imshow(frame);

No devices were detected for the 'winvideo' adaptor. For troubleshooting device detection issues, click here.
错误使用 videoinput (line 235)
There are no devices installed for the specified ADAPTORNAME. See IMAQHWINFO.

出错 camera (line 4)
vid = videoinput('winvideo',1);

出错 run (line 91)
evalin('caller', strcat(script, ';'));