UnityPostRequestSample

UnityPostRequestSample.cs

using System.Collections;
using UnityEngine;
using UnityEngine.Networking;

using Newtonsoft.Json;

/// <summary>
/// This sample code work properly on Unity2020.3 <br/>
/// </summary>
public class UnityPostRequestSample : MonoBehaviour {

    private const string URL = "http://localhost";

    public void ParamRequest()
    {
        var form = new WWWForm();
        form.AddField("param-key", "param-value");

        var request = UnityWebRequest.Post(URL, form);
        request.SetRequestHeader("Content-Type", "application/json");

        Log("Start POST request with parameter.")
        StartCoroutine(Request());
    }

    public void JsonBodyRequest()
    {
        var json = JsonConvert.SerializeObject(new {
            key = "value",
            NestedJson = {
                key = "value"
            }
        })

        var request = new UnityWebRequest(URL, "POST");
            
        var jsonToSend = new System.Text.UTF8Encoding().GetBytes(jsonBody);
        request.uploadHandler = new UploadHandlerRaw(jsonToSend);
        request.downloadHandler = new DownloadHandlerBuffer();

        request.SetRequestHeader("Content-Type", "application/json");

        Log("Start POST request with json body.")
        StartCoroutine(Request());
    }

    private IEnumerator Request()
    {
        // send request, and wait till get response.
        yield return request.SendWebRequest();
                
        if (request.result == UnityWebRequest.Result.ConnectionError || 
            request.result == UnityWebRequest.Result.ProtocolError)
        {
            Log($"Failed get response with error code '{request.error}'.");
        }
        else
        {
            Log($"Succeed response with '{request.responseCode}'.");
            
            // NOTE if you have any expectable object, replace `T` to `ExcpectableClass`
            //
            // var response = JsonConvert.DeserializeObject<T>(request.downloadHandler.text);

            // NOTE if you wanna use callback method
            //
            // Callback()
            //
            // or you can inject variable using parameter
        }
    }   

    private void Callback()
    {
        Log("Not implemented.")
    }

    /// <summary>
    /// If you use custom logger, change implementation.
    /// </summary>
    /// <param name="message">message</param>
    /// <returns></returns>
    private void Log(object message) => Debug.Log(message);
}