Unexpected NullReferenceException in C# when Using HttpClient with Dependency Injection in ASP.NET Core 6
I'm testing a new approach and I'm working on a project and hit a roadblock. I'm having trouble with I'm working on a personal project and I'm encountering a `NullReferenceException` when trying to use `HttpClient` in my ASP.NET Core 6 application with dependency injection. My `HttpClient` is registered in the `Startup.cs` like this: ```csharp public void ConfigureServices(IServiceCollection services) { services.AddHttpClient(); services.AddScoped<IMyService, MyService>(); } ``` In my `MyService` class, I have the following code: ```csharp public class MyService : IMyService { private readonly HttpClient _httpClient; public MyService(HttpClient httpClient) { _httpClient = httpClient; } public async Task<string> GetDataAsync(string url) { var response = await _httpClient.GetAsync(url); response.EnsureSuccessStatusCode(); return await response.Content.ReadAsStringAsync(); } } ``` When I try to call `GetDataAsync` method from a controller like this: ```csharp public class MyController : ControllerBase { private readonly IMyService _myService; public MyController(IMyService myService) { _myService = myService; } [HttpGet] public async Task<IActionResult> Get() { var data = await _myService.GetDataAsync("https://api.example.com/data"); return Ok(data); } } ``` I'm getting a `NullReferenceException` at the line where I call `_httpClient.GetAsync(url)`. I have verified that the DI is working correctly, and `MyService` is being properly instantiated. However, it seems like `_httpClient` is null at runtime. I also checked to ensure that I am not inadvertently creating multiple instances of `MyService`. I've tried cleaning and rebuilding the solution, as well as restarting the development server, but the issue persists. Could this be related to the way I'm configuring `HttpClient` or some lifecycle issues in DI? Any insights would be greatly appreciated! My development environment is macOS. Has anyone else encountered this? What's the best practice here? This issue appeared after updating to C# stable. What are your experiences with this? This is my first time working with C# stable. Is there a simpler solution I'm overlooking? For reference, this is a production microservice. Any suggestions would be helpful.