HTTP API Reference

using Windows.Web.Http;
using System;
using System.Threading.Tasks;

public class HttpExample
{
    public async Task MakeGetRequestAsync()
    {
        using (var httpClient = new HttpClient())
        {
            var uri = new Uri("https://jsonplaceholder.typicode.com/posts/1");
            try
            {
                HttpResponseMessage response = await httpClient.GetAsync(uri);
                response.EnsureSuccessStatusCode(); // Throws if the status code is not success

                string responseBody = await response.Content.ReadAsStringAsync();
                System.Diagnostics.Debug.WriteLine(responseBody);
            }
            catch (HttpRequestException ex)
            {
                System.Diagnostics.Debug.WriteLine($"Request error: {ex.Message}");
            }
        }
    }
}
            

HttpRequestMessage

Represents an HTTP request. You can customize the method, URI, headers, and content.

Properties

• Method: The HTTP method (e.g., GET, POST).
• RequestUri: The URI to send the request to.
• Content: The HTTP content to send with the request.
• Headers: The collection of HTTP request headers.

HttpResponseMessage

Represents an HTTP response. Contains status code, headers, and content.

Properties

• StatusCode: The HTTP status code.
• ReasonPhrase: The reason phrase for the status code.
• Content: The HTTP content received in the response.
• Headers: The collection of HTTP response headers.

Methods

• EnsureSuccessStatusCode(): Throws an exception if the HTTP status code indicates an error.
• Content.ReadAsStringAsync(): Reads the response content as a string.
• Content.ReadAsBufferAsync(): Reads the response content as a buffer.

HttpContent

Represents the HTTP content of a request or response. This is an abstract base class. Concrete implementations include:

• StringContent: For sending plain text or JSON/XML strings.
• StreamContent: For sending data from a stream.
• ByteArrayContent: For sending a byte array.
• MultipartFormDataContent: For sending multipart/form-data.

Common Scenarios

Sending JSON Data

Use StringContent with the application/json media type.

using Windows.Web.Http;
using System;
using System.Text.Json; // Or Newtonsoft.Json

public class JsonExample
{
    public async Task SendJsonPostAsync()
    {
        using (var httpClient = new HttpClient())
        {
            var uri = new Uri("https://jsonplaceholder.typicode.com/posts");
            var postData = new { title = "foo", body = "bar", userId = 1 };
            string jsonString = JsonSerializer.Serialize(postData); // Or Newtonsoft.Json.JsonConvert.SerializeObject(postData);

            using (var content = new StringContent(jsonString, System.Text.Encoding.UTF8, "application/json"))
            {
                HttpResponseMessage response = await httpClient.PostAsync(uri, content);
                response.EnsureSuccessStatusCode();
                string responseBody = await response.Content.ReadAsStringAsync();
                System.Diagnostics.Debug.WriteLine(responseBody);
            }
        }
    }
}
        

Handling Request Headers

You can set common headers on the HttpClient or specific request headers on the HttpRequestMessage.

// Setting default headers
httpClient.DefaultRequestHeaders.UserAgent.ParseAdd("MyUWPApp/1.0");
httpClient.DefaultRequestHeaders.Accept.Add(new Windows.Web.Http.Headers.HttpMediaTypeWithQualityHeaderValue("application/json"));

// Setting request-specific headers
var request = new HttpRequestMessage(HttpMethod.Get, uri);
request.Headers.Add("X-Custom-Header", "MyValue");
var response = await httpClient.SendRequestAsync(request);
        

Handling Redirects

The HttpClient automatically follows redirects by default. You can control this behavior using HttpClient.DefaultRequestHeaders.FollowRedirects.

Security Considerations

For secure communication, always use HTTPS URIs and ensure your application has the necessary capabilities declared in its manifest (e.g., Internet (Client & Server)).

SSL/TLS Certificates

The HttpClient validates SSL/TLS certificates by default. You can optionally configure custom certificate validation callbacks using HttpClient.DefaultRequestHeaders.SetRequestHeader(HttpClient.CertificateValidationHeaderName, "true") and handling the ServerCustomValidation event, though this is generally not recommended unless you have specific security requirements.