【Unity】UnityWebRequest で Json パラメータを送信する

public static class UnityWebRequestExtension
{
    /// <summary>
    /// Json を追加
    /// </summary>
    public static void AddJson(this UnityEngine.Networking.UnityWebRequest self, string json)
    {
        var postData = System.Text.Encoding.UTF8.GetBytes(json);
        self.uploadHandler = new UploadHandlerRaw(postData);
        self.downloadHandler = new DownloadHandlerBuffer();
        self.SetRequestHeader("Content-Type", "application/json");
    }
}

サンプル

var request = new UnityWebRequest("http://hoge", "POST");
// Json パラメータを Header に追加する
request.AddJson(json);