Kdjykuj

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");

var response = client.Execute(request);

var returnedObject = JsonConvert.DeserializeObject<McomCategory>(response.Content);