C# HttpClient and API

Question

I have a web application that pulls data from an API using the HttpClient class. I have a few questions.

1. Is HttpClient optimal for getting data from API? I get a string from APi and deserialize it into an object.
2. A new instance of HttpClient is created each time it is used (for each user). Is it best to use: using (HttpClient client = new HttpClient()) for each request?

Try to find best and optimal solution.

Answer 1

1. Yes, HttpClient is certainly appropriate for using web APIs and deserialization.

2. Creating a new HttpClient for each request is not a good usage. The recommended way is to create HttpClient objects using the IHttpClientFactory interface. Here is a basic usage from MSDN:

    class TodoService
    {
        private readonly IHttpClientFactory _httpClientFactory = null!;
        private readonly ILogger<TodoService> _logger = null!;
   
        public TodoService(
            IHttpClientFactory httpClientFactory,
            ILogger<TodoService> logger) =>
            (_httpClientFactory, _logger) = (httpClientFactory, logger);
   
        public async Task<Todo[]> GetUserTodosAsync(int userId)
        {
            // Create the client
            using HttpClient client = _httpClientFactory.CreateClient();
   
            try
            {
                // Make HTTP GET request
                // Parse JSON response deserialize into Todo types
                Todo[]? todos = await client.GetFromJsonAsync<Todo[]>(
                    $"https://jsonplaceholder.typicode.com/todos?userId={userId}",
                    new JsonSerializerOptions(JsonSerializerDefaults.Web));
   
                return todos ?? Array.Empty<Todo>();
            }
            catch (Exception ex)
            {
                _logger.LogError("Error getting something fun to say: {Error}", ex);
            }
   
            return Array.Empty<Todo>();
        }
    }
   

   }

You can refer to IHttpClientFactory with .NET and Guidelines for using HttpClient