Mryntu

I create an Integration -> Activate -> Obtained the Access Token

Like is described here: http://devdocs.magento.com/guides/v2.2/get-started/authentication/gs-authentication-token.html

And in my test project I get this in response object:
Content:

""message":"Consumer is not authorized to access %resources","parameters":"resources":"Magento_Catalog::categories""
StatusCode:
System.Net.HttpStatusCode.Unauthorized

I create a class Magento:

public class Magento

 private RestClient Client get; set; 
 private string Token get; set; 

 public Magento(string magentoUrl, string token)
 
 Token = token;
 Client = new RestClient(magentoUrl);
 

 private RestRequest CreateRequest(string endPoint, Method method, string token)
 
 var request = new RestRequest(endPoint, method);
 request.RequestFormat = DataFormat.Json;
 request.AddHeader("Authorization", "Bearer " + token);
 request.AddHeader("Accept", "application/json");
 return request;
 

 public string CreateCategory(int id, int ParentId, string categoryName, bool IsActive, bool IncludeInMenu)
 
 var request = CreateRequest("/rest/V1/categories", Method.POST, Token);
 var cat = new ProductCategory();
 var category = new Category();
 category.Id = id;
 category.ParentId = ParentId;
 category.Name = categoryName;
 category.IsActive = IsActive;
 category.IncludeInMenu = IncludeInMenu;
 cat.Category = category;

 string json = JsonConvert.SerializeObject(cat, Formatting.Indented);

 request.AddParameter("application/json", json, ParameterType.RequestBody);

 var response = Client.Execute(request);
 if (response.StatusCode == System.Net.HttpStatusCode.OK)
 
 return response.Content;
 
 else
 
 return ":(" + response.Content;
 
 


 public void GetSku(string token, string sku)
 
 var request = CreateRequest("/rest/V1/products/" + sku, Method.GET, token);

 var response = Client.Execute(request);

 if (response.StatusCode == System.Net.HttpStatusCode.OK)
 
 M2Product product = JsonConvert.DeserializeObject<M2Product>(response.Content);

 

 

 public string CreateCategory(string categoryName)
 
 var request = CreateRequest("/rest/V1/categories", Method.POST, Token);
 var cat = new ProductCategory();
 var category = new Category();
 category.Name = categoryName;
 cat.Category = category;

 string json = JsonConvert.SerializeObject(cat, Formatting.Indented);

 request.AddParameter("application/json", json, ParameterType.RequestBody);

 var response = Client.Execute(request);
 if (response.StatusCode == System.Net.HttpStatusCode.OK)
 
 return response.Content;
 
 else
 
 return ":( "+ response.Content;
 
 



public class ProductCategory


 [JsonProperty("category")]
 public Category Category get; set; 


public class Category


 [JsonProperty("id")]
 public int Id get; set; 

 [JsonProperty("parent_id")]
 public int ParentId get; set; 

 [JsonProperty("name")]
 public string Name get; set; 

 [JsonProperty("is_active")]
 public bool IsActive get; set; 

 [JsonProperty("position")]
 public int Position get; set; 

 [JsonProperty("level")]
 public int Level get; set; 

 [JsonProperty("children")]
 public string Children get; set; 

 [JsonProperty("created_at")]
 public string CreatedAt get; set; 

 [JsonProperty("updated_at")]
 public string UpdatedAt get; set; 

 [JsonProperty("path")]
 public string Path get; set; 

 [JsonProperty("available_sort_by")]
 public IList<string> AvailableSortBy get; set; 

 [JsonProperty("include_in_menu")]
 public bool IncludeInMenu get; set; 



public class StockItem


 [JsonProperty("item_id")]
 public int ItemId get; set; 

 [JsonProperty("product_id")]
 public int ProductId get; set; 

 [JsonProperty("stock_id")]
 public int StockId get; set; 

 [JsonProperty("qty")]
 public int Qty get; set; 

 [JsonProperty("is_in_stock")]
 public bool IsInStock get; set; 

 [JsonProperty("is_qty_decimal")]
 public bool IsQtyDecimal get; set; 

 [JsonProperty("show_default_notification_message")]
 public bool ShowDefaultNotificationMessage get; set; 

 [JsonProperty("use_config_min_qty")]
 public bool UseConfigMinQty get; set; 

 [JsonProperty("min_qty")]
 public int MinQty get; set; 

 [JsonProperty("use_config_min_sale_qty")]
 public int UseConfigMinSaleQty get; set; 

 [JsonProperty("min_sale_qty")]
 public int MinSaleQty get; set; 

 [JsonProperty("use_config_max_sale_qty")]
 public bool UseConfigMaxSaleQty get; set; 

 [JsonProperty("max_sale_qty")]
 public int MaxSaleQty get; set; 

 [JsonProperty("use_config_backorders")]
 public bool UseConfigBackorders get; set; 

 [JsonProperty("backorders")]
 public int Backorders get; set; 

 [JsonProperty("use_config_notify_stock_qty")]
 public bool UseConfigNotifyStockQty get; set; 

 [JsonProperty("notify_stock_qty")]
 public int NotifyStockQty get; set; 

 [JsonProperty("use_config_qty_increments")]
 public bool UseConfigQtyIncrements get; set; 

 [JsonProperty("qty_increments")]
 public int QtyIncrements get; set; 

 [JsonProperty("use_config_enable_qty_inc")]
 public bool UseConfigEnableQtyInc get; set; 

 [JsonProperty("enable_qty_increments")]
 public bool EnableQtyIncrements get; set; 

 [JsonProperty("use_config_manage_stock")]
 public bool UseConfigManageStock get; set; 

 [JsonProperty("manage_stock")]
 public bool ManageStock get; set; 

 [JsonProperty("low_stock_date")]
 public object LowStockDate get; set; 

 [JsonProperty("is_decimal_divided")]
 public bool IsDecimalDivided get; set; 

 [JsonProperty("stock_status_changed_auto")]
 public int StockStatusChangedAuto get; set; 


public class ExtensionAttributes


 [JsonProperty("stock_item")]
 public StockItem StockItem get; set; 


public class CustomAttribute


 [JsonProperty("attribute_code")]
 public string AttributeCode get; set; 

 [JsonProperty("value")]
 public object Value get; set; 


public class M2Product


 [JsonProperty("id")]
 public int Id get; set; 

 [JsonProperty("sku")]
 public string Sku get; set; 

 [JsonProperty("name")]
 public string Name get; set; 

 [JsonProperty("attribute_set_id")]
 public int AttributeSetId get; set; 

 [JsonProperty("price")]
 public int Price get; set; 

 [JsonProperty("status")]
 public int Status get; set; 

 [JsonProperty("visibility")]
 public int Visibility get; set; 

 [JsonProperty("type_id")]
 public string TypeId get; set; 

 [JsonProperty("created_at")]
 public string CreatedAt get; set; 

 [JsonProperty("updated_at")]
 public string UpdatedAt get; set; 

 [JsonProperty("extension_attributes")]
 public ExtensionAttributes ExtensionAttributes get; set; 

 [JsonProperty("product_links")]
 public IList<object> ProductLinks get; set; 

 [JsonProperty("options")]
 public IList<object> Options get; set; 

 [JsonProperty("media_gallery_entries")]
 public IList<object> MediaGalleryEntries get; set; 

 [JsonProperty("tier_prices")]
 public IList<object> TierPrices get; set; 

 [JsonProperty("custom_attributes")]
 public IList<CustomAttribute> CustomAttributes get; set; 

And a form

public partial class Form1 : Form

 static private string siteAddress = "http://magento.com/";
 static private string token = "d21312d97hosbblablablaqtqawlbw";
 Magento objMagneto;

 public Form1()
 
 InitializeComponent();
 objMagneto = new Magento(siteAddress, token);
 

 private void button1_Click(object sender, EventArgs e)
 
 this.Close();
 

 private void adgClasa_Click(object sender, EventArgs e)
 
 MessageBox.Show(objMagneto.CreateCategory(10, 0, "PC Components", true, true)); // id, ParentId, name, IsActive, IncludeInMenu

 

I see you are using RestClient and Newtonsoft Json both great libraries!

Using the 2.2 REST API and RestClient I use the following: -

var client = new RestClient(<endpoint>)

 Encoding = Encoding.UTF8,
 Authenticator = OAuth1Authenticator.ForProtectedResource(<ConsumerKey>, <ConsumerSecret>, <AccessToken>, <AccessTokenSecret>)
;
var request = new RestRequest("rest/V1/categories", Method.POST);
request.AddHeader("Content-Type", "application/json");
request.Parameters.Add(new Parameter("category", JsonConvert.SerializeObject(new category , Formatting.None), ContentType.Json, ParameterType.RequestBody));
var response = client.Execute(request);
var returnedObject = JsonConvert.DeserializeObject<McomCategory>(response.Content);