System.Net.Http.HttpResponseMessage Class

`System.Net.Http.HttpResponseMessage` Class

Represents an HTTP response message, including the status code and data.

In the .NET Framework, the HttpResponseMessage class is a core component for working with HTTP responses when using the HttpClient class. It encapsulates all the information that a server sends back to a client after processing an HTTP request. This includes the HTTP version, status code, reason phrase, headers, and the content of the response.

This class is part of the System.Net.Http namespace, which provides classes for sending HTTP requests and receiving HTTP responses.

Inheritance

public class HttpResponseMessage : IDisposable

object

System.Object
System.Net.Http.HttpResponseMessage

Implemented interfaces:

System.IDisposable

Fields

This class has no fields.

Properties

Content System.Net.Http.HttpContent? { get; set; }
Gets or sets the HTTP content of the response.
Headers System.Net.Http.Headers.HttpResponseHeaders { get; }
Gets the collection of HTTP response headers.
RequestMessage System.Net.Http.HttpRequestMessage? { get; set; }
Gets or sets the HTTP request message that led to this response message.
StatusCode System.Net.HttpStatusCode { get; set; }
Gets or sets the status code of the response.
ReasonPhrase string? { get; set; }
Gets or sets the reason phrase associated with the HTTP status code.
Version System.Version { get; set; }
Gets or sets the HTTP message version.
IsSuccessStatusCode bool { get; }
Gets a value indicating whether the status code was successful.

Methods

EnsureSuccessStatusCode()
public void EnsureSuccessStatusCode()

Throws an exception if the response status code indicates failure.
Dispose()
public void Dispose()

Disposes of the HTTP response message.
ToString()
public string ToString()

Returns a string that represents the current object.

Remarks

The HttpResponseMessage class is fundamental to consuming HTTP services in .NET. When you use HttpClient.SendAsync() or HttpClient.GetAsync(), the result is an HttpResponseMessage.

Key aspects of HttpResponseMessage:

Status Code: Indicates the outcome of the request (e.g., 200 OK, 404 Not Found, 500 Internal Server Error). The StatusCode property holds this value.
Reason Phrase: A textual description of the status code (e.g., "OK", "Not Found"). The ReasonPhrase property provides this.
Headers: Contains metadata about the response, such as content type, content length, caching directives, etc. Accessed via the Headers property.
Content: Represents the body of the HTTP response. This can be anything from plain text to JSON, XML, or binary data. The Content property is of type HttpContent.
Request Message: A reference to the original HttpRequestMessage that generated this response is available via the RequestMessage property. This can be useful for debugging or correlating requests and responses.
Success Status Check: The IsSuccessStatusCode property is a convenient way to check if the status code falls within the 2xx range, indicating a successful operation. The EnsureSuccessStatusCode() method automates throwing an exception for non-successful status codes.
Resource Management: The HttpResponseMessage implements IDisposable because its Content property might hold unmanaged resources (like network streams). It's crucial to dispose of HttpResponseMessage objects to release these resources, typically using a using statement.

Examples

Here's a common scenario demonstrating how to use HttpResponseMessage:


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

                    public class Example
                    {
                        public async Task FetchDataAsync()
                        {
                            using (var client = new HttpClient())
                            {
                                try
                                {
                                    HttpResponseMessage response = await client.GetAsync("https://jsonplaceholder.typicode.com/posts/1");

                                    // Check if the request was successful
                                    response.EnsureSuccessStatusCode(); // Throws an exception for non-2xx status codes

                                    // Access response properties
                                    HttpStatusCode statusCode = response.StatusCode;
                                    string reasonPhrase = response.ReasonPhrase;
                                    bool isSuccess = response.IsSuccessStatusCode;

                                    // Read the response content
                                    if (response.Content is not null)
                                    {
                                        string responseBody = await response.Content.ReadAsStringAsync();
                                        System.Console.WriteLine($"Status Code: {statusCode}");
                                        System.Console.WriteLine($"Reason Phrase: {reasonPhrase}");
                                        System.Console.WriteLine($"Response Body: {responseBody}");
                                    }
                                }
                                catch (HttpRequestException e)
                                {
                                    System.Console.WriteLine($"Request exception: {e.Message}");
                                }
                            }
                        }
                    }

In this example:

An HttpClient is created and used to send a GET request.
The using statement ensures that the HttpClient and the HttpResponseMessage are properly disposed of.
EnsureSuccessStatusCode() is called to automatically handle unsuccessful HTTP status codes.
Properties like StatusCode, ReasonPhrase, and IsSuccessStatusCode are accessed.
The response content is read as a string using response.Content.ReadAsStringAsync().