cv::dnn::dnn4_v20191202::Net::Impl::setUpNet DNN module was not built with CUDA backend; switching to CPU

[HenryLee-coder]

Summary of your issue

Opencvsharp calls Darknet, where net.setpreferablebackend explicitly sets CUDA, but it uses CPU

Environment

win10+vs2019+opencvsharp4.2,

What did you do when you faced the problem?

//write here

Example code:

paste your core code
```net.SetPreferableBackend(Net.Backend.CUDA);
net.SetPreferableTarget(Net.Target.CUDA_FP16);

## Output:

paste your output

[ WARN:0] global C:\lib\opencv2\modules\dnn\src\dnn.cpp (1363) cv::dnn::dnn4_v20191202::Net::Impl::setUpNet DNN module was not built with CUDA backend; switching to CPU
## What did you intend to be?

What can I do to use CUDA? Is there a routine reference

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[Yuan262]

解决了吗？大佬