How to convert HttpResponseMessage to ViewResult?

Unfortunately, there is no support for direct conversion from HttpResponseMessage to ViewResult.

Implementation:

1. Create a model class for API response.

using System.Net;

public class ApiReponseModel<T>
{
    public HttpStatusCode StatusCode { get; private set; }
    public string ResponseMessage { get; private set; }
    public T Data { get; private set; }

    public ApiReponseModel(HttpStatusCode statusCode)
    {
        StatusCode = statusCode;
    }

    public ApiReponseModel(HttpStatusCode statusCode, T data)
    {
        StatusCode = statusCode;
        Data = data;
    }

    public ApiReponseModel(HttpStatusCode statusCode, string responseMessage)
    {
        StatusCode = statusCode;
        ResponseMessage = responseMessage;
    }

    public ApiReponseModel(HttpStatusCode statusCode, string responseMessage, T data)
    {
        StatusCode = statusCode;
        ResponseMessage = responseMessage;
        Data = data;
    }
}

2. Implement the helper method for converting HttpResponseMessage to ViewResult.

using Newtonsoft.Json;
using System.Net.Http;
using System.Threading.Tasks;
using System.Web.Mvc;

public static class ViewResultHelper
{
    public static async Task<ViewResult> ToViewResultAsync<T>(
        this HttpResponseMessage response,
        string viewName,
        string errorViewName = "/Views/Shared/Error.cshtml")
    {
        if (!response.IsSuccessStatusCode)
        {
            var errorRespContentString = await response.Content.ReadAsStringAsync();

            return new ViewResult
            {
                ViewName = errorViewName,
                ViewData = new ViewDataDictionary()
                {
                    Model = new ApiReponseModel<T>
                    (
                        response.StatusCode,
                        response.ReasonPhrase,
                        JsonConvert.DeserializeObject<T>(errorRespContentString)
                    )
                }
            };
        }

       var respContentString = await response.Content.ReadAsStringAsync();

        return new ViewResult
        {
            ViewName = viewName,
            ViewData = new ViewDataDictionary()
            {
                Model = new ApiReponseModel<T>
                (
                    response.StatusCode,
                    JsonConvert.DeserializeObject<T>(respContentString)
                 )
            }
        };
    }
}

3. Caller for the helper method in your controller action.

/* Mocked response */
/*
User user = new User { Name = "Test User" };
var response = new HttpResponseMessage(HttpStatusCode.OK)
{
    Content = new StringContent(JsonConvert.SerializeObject(user), Encoding.UTF8, "application/json")
};
*/

return await response.ToViewResultAsync<User>("<Your View Name>");

4. In your view, it should expect the Model with ApiReponseModel<T> type.

@model /* Your Project namespace */.Models.ApiReponseModel<User>

@using Newtonsoft.Json


<!-- To get API response body data -->
<code>
    @JsonConvert.SerializeObject(Model.Data, Formatting.Indented)
</code>