asp.net - HttpClient 的所有方法是否都在内部调用 SendAsync 方法？

Question

HttpClient 的所有方法，即 GetAsync、PostAsync 等是否在内部调用 SendAsync 方法？

Answer 1

是的， HttpClient 使用 HttpMessageHandler 下面执行所有 HTTP 请求。 HttpMessageHandler方法 Task<HttpResponseMessage> SendAsync(HttpRequestMessage, CancellationToken) 是HttpClient 所称的.

抽象类的默认实现HttpMessageHandler是 HttpClientHandler .

You can pass in your own HttpMessageHandler implementation to the HttpClient constructor that takes one.尽管您不太可能需要，但还是有应用程序的。例如，如果您想记录每个请求您的 HttpClient使。你可以做一个 LoggingHttpMessageHandler HttpMessageHandler 的装饰器.

using (var handler = new HttpClientHandler())
using (var loggingHandler = new LoggingHttpClientHandler(handler, logger))
using (var client = new HttpClient(loggingHandler))
{
    // Logs "GET https://www.google.com/"
    var response = await client.GetAsync("https://www.google.com/");
    ...
}