asp.net-core – .NET Core HttpClient是否具有拦截器的概念？

用法：

var handler = new ExampleHttpHandler(fooService);

var client = new HttpClient(new ExampleHttpHandler(handler));

var response = await client.GetAsync("http://google.com");

执行：

public class ExampleHttpHandler : DelegatingHandler
{
    //register the handler itself in DI to inject dependencies
    public ExampleHttpHandler(FooService service) : this(service,null)
    {
    }

    public ExampleHttpHandler(FooService service,HttpMessageHandler innerHandler)
    {
        //default handler should be the last!
        InnerHandler = innerHandler ?? new HttpClientHandler();
    }

    protected override async Task<HttpResponseMessage> SendAsync(
        HttpRequestMessage request,CancellationToken cancellationToken)
    {
        //add any logic here
        return await base.SendAsync(request,cancellationToken);
    }
}