I am trying to port a code from .Net to Unity C# and I am stuck on a syntax including a callback.
Basically, I had to replace the .Net 'HttpClient' library by this one, also called 'HttpClient'. But the 'Get' syntax is not the same and uses a Callback. I am quite new to C# and Http queries and don't know how to deal with this syntax to get the expected return.
The original function written in .Net:
internal static JObject GetToBackOffice(string action)
{
var url = backOfficeUrl;
url = url + action;
HttpClient httpClient = new HttpClient();
var response =
httpClient.GetAsync(url
).Result;
if (response.StatusCode == System.Net.HttpStatusCode.OK)
{
var idProcess = Newtonsoft.Json.Linq.JObject.Parse(response.Content.ReadAsStringAsync().Result);
return idProcess;
}
else
return null;
The C# code I am writing for Unity:
internal class Utils
{
internal static JObject GetToBackOffice(string action)
{
var url = backOfficeUrl;
url = url + action;
HttpClient httpClient = new HttpClient();
JObject idProcess = new JObject();
httpClient.GetString(new Uri(url),
(response) =>
{
// Raised when the download completes
if (response.StatusCode == System.Net.HttpStatusCode.OK)
{
idProcess = Newtonsoft.Json.Linq.JObject.Parse(response.Data);
}
else
{
idProcess = null;
}
});
// Here I would like to wait for the response, so that idProcess is filled with the received data before returning
return idProcess;
}
public class Action
{
public bool SendData(string id, string secretKey, FakeData data)
{
var idProcess = Utils.GetToBackOffice(String.Format("Events/{0}/infos",id));
//...I do then something with idProcess
//Currently, when I use idProcess here, it is still empty since the GetString response hasn't been received yet when this line is executed
return true;
}
}
public class EventHubSimulator : MonoBehaviour
{
void Start()
{
//Fill the parameters (I skip the details)
string oId = ...;
string secretKey = ...;
var vh = ...;
Action action = new Action();
action.SendData(oId, secretKey, vh);
}
}
My issue is that after the GetToBackOffice function, my code directly uses 'idProcess' for something else but this object is empty because the response was not received yet. I would like to wait for the response before my function returns.
I hope I was clear enough. I know that similar question have already been posted but couldn't find a solution to my specific issue.
Edit:
Finally I used a coroutine as Nain suggested but couldn't get what I expected the way he said. This way seems to work (event though it might not be a good way to do it).
public class EventHubSimulator : MonoBehaviour
{
void Start()
{
//Fill the parameters (I skip the details)
string oId = ...;
string secretKey = ...;
var vh = ...;
Utils utils = new Utils();
StartCoroutine(utils.SendData(oId, secretKey, vh));
}
}
public class Utils: MonoBehaviour
{
private const string backOfficeUrl = "http://myurl/api/";
public CI.HttpClient.HttpResponseMessage<string> response;
public IEnumerator SendData(string id, string secretKey, FakeData data)
{
response = null;
yield return GetToBackOffice(String.Format("Events/{0}/infos", id)); //Make a Http Get request
//The next lines are executed once the response has been received
//Do something with response
Foo(response);
}
IEnumerator GetToBackOffice(string action)
{
var url = backOfficeUrl;
url = url + action;
//Make a Http Get request
HttpClient httpClient = new HttpClient();
httpClient.GetString(new Uri(url), (r) =>
{
// Raised when the download completes
if (r.StatusCode == System.Net.HttpStatusCode.OK)
{
//Once the response has been received, write it in the global variable
response = r;
Debug.Log("Response received : " + response);
}
else
{
Debug.Log("ERROR =============================================");
Debug.Log(r.ReasonPhrase);
throw new Exception(r.ReasonPhrase);
}
});
//Wait for the response to be received
yield return WaitForResponse();
Debug.Log("GetToBackOffice coroutine end ");
}
IEnumerator WaitForResponse()
{
Debug.Log("WaitForResponse Coroutine started");
//Wait for response to become be assigned
while (response == null)
{
yield return new WaitForSeconds(0.02f);
}
Debug.Log("WaitForResponse Coroutine ended");
}
}
