我应该对每个功能使用HttpClient还是对整个应用程序使用HttpClient？

Question

I'm creating .NET wrapper for some REST type API. I'm using HttpClient for communication (sending/recieving Json). There are many async methods.

Verification is via cookie that I'm receiving and storing in cookiecontainer. Should I have separate httpclient for every function or one global httpClient? If one separate for each function, what is the best method to share cookiecontainer and custom headers that are attached to every request?

Answer 1

I suggest keep the number same as the API you're calling (this is how I coded mine), meaning if you're calling to Twitter API, just keep one instance of HttpClient for that, and if you're accessing Facebook API in the same time, keep another one for that.

Keep in mind that some metadata cannot be change after a HttpClient has been created (eg DefaultRequestHeaders), which make sense since a HttpClient is meant to be reuse to make multiple calls (eg easy for cookies or auth information sharing).

Answer 2

Definitely per function, in a using statement. Custom headers can be stored in a static variable as long as they're only being read from. The cookie container would likely require locking when working with any instance members.