Hi Rajesh,
HttpClient is the correct thing to work with REST service.
However error 404 bad request means your request url is not correct, please double check it.
--James
<THE CONTENT IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, WHETHER EXPRESS OR IMPLIED>
Thanks
MSDN Community Support
Please remember to "Mark as Answer" the responses that resolved your issue. It is a common way to recognize those who have helped you, and makes it easier for other visitors to find the resolution later.