Webapi call from mvc application

Question

I have created two projects in a same solution, one for mvc application and other for web api.

When i am calling my web api method from PostMan or any HttpClient, i am able to receive the response as expected.

However when i am calling the same method in MVC application, the application keeps on running with no response received. No specific exceptions are logged or displayed by visual studio.

I have copied the code which i am using for reference. Any help will be highly appreciated.

public class UserFacade
{
 HttpClient _client;
 string url = "http://localhost:50759/api/v1/login";
 public void LoginUser(string userName, string password)
 {
 _client = new HttpClient
 {
 BaseAddress = new Uri(url)
 };
 _client.DefaultRequestHeaders.Accept.Clear();
 _client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
 var model = new UserModel
 {
 UserName = userName,
 UserPassword = password
 };
 var userModel = JsonConvert.SerializeObject(model);
 var content = new StringContent(userModel, Encoding.UTF8, "application/json");
 GetUserTask(_client, content).Wait();
 }
 private async Task GetUserTask(HttpClient client, StringContent content)
 {
 using (client)
 { 
 HttpResponseMessage res = await client.PostAsync(url, content);
 res.EnsureSuccessStatusCode();
 if (res.IsSuccessStatusCode)
 {
 var response = await res.Content.ReadAsStringAsync();
 JavaScriptSerializer JSserializer = new JavaScriptSerializer();
 //deserialize to your class
 //var userResponse = JSserializer.Deserialize<UserResponse>(response);
 }
 }
 }
}

Just for the information that i have made two startup projects in the solution and running the code from there.

Answer 1

You are deadlocking yourself. Make sure that you do not capture the context when making the async calls:

private async Task GetUserTask(HttpClient client, StringContent content)
{
 using (client)
 {
 HttpResponseMessage res = await client.PostAsync(url, content).ConfigureAwait(false);
 res.EnsureSuccessStatusCode();
 if (res.IsSuccessStatusCode)
 {
 var response = await res.Content.ReadAsStringAsync().ConfigureAwait(false);
 }
 }
}

Notice the .ConfigureAwait(false) that I have added to both your async calls.

This being said, it is a complete waste to be making an asynchronous call and then blocking it like this:

GetUserTask(_client, content).Wait();

You are killing absolutely all the benefits of asynchronous calls. I would very strongly recommend you using the async version of the code:

public async Task LoginUser(string userName, string password)
{
 _client = new HttpClient
 {
 BaseAddress = new Uri(url)
 };
 _client.DefaultRequestHeaders.Accept.Clear();
 _client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
 var model = new UserModel
 {
 UserName = userName,
 UserPassword = password
 };
 var userModel = JsonConvert.SerializeObject(model);
 var content = new StringContent(userModel, Encoding.UTF8, "application/json");
 await GetUserTask(_client, content);
}

and then of course have an async action controller action which will consume the async method:

public async Task<ActionResult> Index()
{
 await new UserFacade().LoginUser("user", "secret");
 return View();
}

• Amit Gupta: Thank you Darin for the help.