System.Net.Http.HttpClientHandler

Namespace: System.Net.Http

Provides a programming model for sending HTTP requests and receiving HTTP responses from a resource identified by a URI. This class handles the details of HTTP communication, including managing connections, cookies, and authentication.

Constructors

Signature Description
HttpClientHandler() Initializes a new instance of the HttpClientHandler class.

Properties

Name Type Description
AllowAutoRedirect bool Gets or sets a value that indicates whether the HTTP handler should automatically follow redirection responses (e.g., HTTP 3xx). Default is true.
AutomaticDecompression DecompressionMethods Gets or sets a value that indicates whether the HTTP client supports automatic decompression of supported responses. Default is DecompressionMethods.GZip | DecompressionMethods.Deflate.
ClientCertificateOptions ClientCertificateOption Gets or sets a value that indicates how the client certificate is provided.
CookieContainer CookieContainer Gets or sets the container for cookies that are sent with requests.
Credentials ICredentials Gets or sets the credentials used for basic authentication.
MaxAutomaticRedirections int Gets or sets the maximum number of automatic redirections. Default is 50.
Proxy IWebProxy Gets or sets the proxy used to send requests.
UseCookies bool Gets or sets a value that indicates whether the handler uses cookies. Default is true.
UseProxy bool Gets or sets a value that indicates whether the handler uses the proxy. Default is true.

Methods

Signature Description
SendAsync(HttpRequestMessage request, CancellationToken cancellationToken) Sends an HTTP request to the specified host and gets the response headers and status code.
Parameters:
  • request: The HTTP request message to send.
  • cancellationToken: The token to monitor for cancellation requests.
Returns: A task object representing the asynchronous operation.
Dispose() Releases the unmanaged resources used by the HttpClientHandler and optionally releases the managed resources.

Usage Example

The HttpClientHandler is typically used to customize the behavior of an HttpClient instance.


using System;
using System.Net;
using System.Net.Http;
using System.Threading.Tasks;

public class Example
{
    public static async Task Main(string[] args)
    {
        // Create an HttpClientHandler instance
        var handler = new HttpClientHandler
        {
            // Configure custom behavior
            UseCookies = true,
            CookieContainer = new CookieContainer(),
            AllowAutoRedirect = true,
            MaxAutomaticRedirections = 10,
            Proxy = new WebProxy("http://myproxy.com:8080")
        };

        // Create an HttpClient instance with the custom handler
        using (HttpClient client = new HttpClient(handler))
        {
            try
            {
                HttpResponseMessage response = await client.GetAsync("https://www.example.com");
                response.EnsureSuccessStatusCode(); // Throws if HTTP status code is an error

                string responseBody = await response.Content.ReadAsStringAsync();
                Console.WriteLine(responseBody.Substring(0, 200) + "..."); // Print first 200 chars
            }
            catch (HttpRequestException e)
            {
                Console.WriteLine($"Request error: {e.Message}");
            }
        }
    }
}

Related Topics