don't know if this new parameter shit is user-friendly :-/

PocketSharp.Console/Program.cs

@@ -1,6 +1,7 @@
 using System;
 using PocketSharp;
 using PocketSharp.Models.Authentification;
+using PocketSharp.Models.Parameters;
 
 namespace PocketSharp.Console
 {
@@ -16,7 +17,10 @@ namespace PocketSharp.Console
       PocketClient client = new PocketClient("15396-f6f92101d72c8e270a6c9bb3");
       client.AccessCode = "a85134a7-243c-6656-ab82-97c901";
 
-      client.Retrieve();
+      client.Retrieve(new RetrieveParameters()
+      {
+        Favorite = true
+      });
 
       System.Console.ReadKey();
     }

PocketSharp/Components/Retrieve.cs

@@ -4,19 +4,28 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
+using PocketSharp.Models.Parameters;
 
 namespace PocketSharp
 {
   public partial class PocketClient
   {
-    public bool Retrieve()
+    public bool Retrieve(RetrieveParameters para)
     {
-      var parameters = new List<Parameter>()
+      //var parameters = new List<Parameter>()
+      //{
+      //  new Parameter { Name = "favorite", Value = "1", Type = ParameterType.GetOrPost }
+      //};
+
+      var parameters = new RetrieveParameters()
       {
-        new Parameter { Name = "favorite", Value = "1", Type = ParameterType.GetOrPost }
+        Favorite = true,
+        State = StateEnum.all
       };
 
-      Retrieve result = GetResource<Retrieve>("get", parameters);
+      var paramss = parameters.Convert();
+
+      Retrieve result = GetResource<Retrieve>("get", parameters.Convert());
 
       return true;
     }

PocketSharp/Models/Parameters/ParameterBase.cs

@@ -0,0 +1,21 @@
+using RestSharp;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace PocketSharp.Models.Parameters
+{
+  public abstract class ParameterBase
+  {
+    protected Parameter CreateParam(string name, object value, ParameterType type = ParameterType.GetOrPost)
+    {
+      return new Parameter()
+      {
+        Name = name,
+        Value = value,
+        Type = type
+      };
+    }
+  }
+}

PocketSharp/Models/Parameters/RetrieveParameters.cs

@@ -0,0 +1,60 @@
+using RestSharp;
+using System;
+using System.Collections.Generic;
+using System.Runtime.Serialization;
+
+namespace PocketSharp.Models.Parameters
+{
+  public class RetrieveParameters : ParameterBase
+  {
+    public StateEnum? State { get; set; }
+
+    public bool? Favorite { get; set; }
+
+    public string Tag { get; set; }
+
+    public ContentTypeEnum? ContentType { get; set; }
+
+    public SortEnum? Sort { get; set; }
+
+
+    public List<Parameter> Convert()
+    {
+      List<Parameter> parameters = new List<Parameter>();
+
+      if(State != null)
+      {
+        parameters.Add(CreateParam("state", State.ToString()));
+      }
+      if(Favorite != null)
+      {
+        parameters.Add(CreateParam("favorite", (bool)Favorite ? "1" : "0"));
+      }
+
+      return parameters;
+    }
+  }
+
+
+  public enum StateEnum
+  {
+    unread,
+    archive,
+    all
+  }
+
+  public enum SortEnum
+  {
+    newest,
+    oldest,
+    title,
+    site
+  }
+
+  public enum ContentTypeEnum
+  {
+    article,
+    video,
+    image
+  }
+}

PocketSharp/PocketSharp.csproj

@@ -52,6 +52,8 @@
     <Compile Include="JsonDeserializer.cs" />
     <Compile Include="Models\Authentification\AccessCode.cs" />
     <Compile Include="Models\Authentification\RequestCode.cs" />
+    <Compile Include="Models\Parameters\ParameterBase.cs" />
+    <Compile Include="Models\Parameters\RetrieveParameters.cs" />
     <Compile Include="Models\PocketItem.cs" />
     <Compile Include="Models\ResponseBase.cs" />
     <Compile Include="Models\Retrieve.cs" />