I have this web api service:

```
 [HttpPost]
 public bool Post(UserModel newUser)
 {
    return regRepo.AddUser(newUser);
 }

```

I want to call it from Xamarin.Forms project, so I made this:

```
   private void AddUser(object obj)
    {
        var user = obj as UserModel;
        var url = @"http://localhost:57615/api/UsersApi/";
        var uri = new Uri(url);
        var client = new HttpClient();
        var json =  JsonConvert.SerializeObject(user);
        var content = new StringContent(json, Encoding.UTF8, "application/json");

        var response = client.PostAsync(uri, content);
     }

```

but it never call the service, I used Postman to make sure the URL is correct, and it works

**EDIT**

I changed the method signature to be `async` as klm\_ suggested, but this error occurs:

> 
> the Application is in break mode
> 
> 
> 

[![enter image description here](https://i.stack.imgur.com/1hMua.png)](https://i.stack.imgur.com/1hMua.png)