How to Call normal C# Web service from Xamarin android application in vs2012 ?

using System;

using Android.App;
using Android.Content;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.OS;
using webserviceexample.com.cdy.ws;
using System.Net;
using System.IO;
using System.Text;

namespace webserviceexample
{
    [Activity(Label = "webserviceexample", MainLauncher = true, Icon = "@drawable/icon")]
    public class Activity1 : Activity
    {
        int count = 1;

        protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);

            // Set our view from the "main" layout resource
            SetContentView(Resource.Layout.Main);

            // Get our button from the layout resource,
            // and attach an event to it
            Button button = FindViewById<Button>(Resource.Id.MyButton);
            TextView lable = FindViewById<textview>(Resource.Id.lbltxt);
           com.cdy.ws.Androidhelloo dd = new com.cdy.ws.Androidhelloo();
          lable.Text = dd.HelloWorld();
            button.Click += delegate { button.Text = string.Format("{0} clicks!", count++); };
        }
    }
}</textview>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Web.Services.Protocols;

namespace AndroidHello
    {
    /// <summary>
    /// Summary description for Androidhelloo
    /// </summary>
    [WebService(Namespace = "http://127.0.0.1:8012/Androidhelloo.asmx")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    [System.ComponentModel.ToolboxItem(false)]
    // To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line.
     [System.Web.Script.Services.ScriptService]

    public class Androidhelloo : System.Web.Services.WebService
        {
        [SoapDocumentMethod(Action = "http://127.0.0.1:8012/Androidhelloo.asmx")]
        [WebMethod]
        public string HelloWorld()
            {

            return "Hello World";
            }
        public string Namespace { get; set; }
        }

    }

//------------------------------------------------------------------------------
// <auto-generated>
//     This code was generated by a tool.
//     Runtime Version:4.0.30319.18052
//
//     Changes to this file may cause incorrect behavior and will be lost if
//     the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------

// 
// This source code was auto-generated by Microsoft.VSDesigner, Version 4.0.30319.18052.
// 
#pragma warning disable 1591

namespace webserviceexample.com.cdy.ws {
    using System;
    using System.Web.Services;
    using System.Diagnostics;
    using System.Web.Services.Protocols;
    using System.Xml.Serialization;
    using System.ComponentModel;
    
    
    /// <remarks />
    [System.CodeDom.Compiler.GeneratedCodeAttribute("System.Web.Services", "4.0.30319.17929")]
    [System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.ComponentModel.DesignerCategoryAttribute("code")]
    [System.Web.Services.WebServiceBindingAttribute(Name="AndroidhellooSoap", Namespace="http://127.0.0.1:8012/Androidhelloo.asmx")]
    public partial class Androidhelloo : System.Web.Services.Protocols.SoapHttpClientProtocol {
        
        private System.Threading.SendOrPostCallback HelloWorldOperationCompleted;
        
        private bool useDefaultCredentialsSetExplicitly;
        
        /// <remarks />
        public Androidhelloo() {
            this.Url = "http://127.0.0.1:8012/Androidhelloo.asmx";
            if ((this.IsLocalFileSystemWebService(this.Url) == true)) {
                this.UseDefaultCredentials = true;
                this.useDefaultCredentialsSetExplicitly = false;
            }
            else {
                this.useDefaultCredentialsSetExplicitly = true;
            }
        }
        
        public new string Url {
            get {
                return base.Url;
            }
            set {
                if ((((this.IsLocalFileSystemWebService(base.Url) == true) 
                            && (this.useDefaultCredentialsSetExplicitly == false)) 
                            && (this.IsLocalFileSystemWebService(value) == false))) {
                    base.UseDefaultCredentials = false;
                }
                base.Url = value;
            }
        }
        
        public new bool UseDefaultCredentials {
            get {
                return base.UseDefaultCredentials;
            }
            set {
                base.UseDefaultCredentials = value;
                this.useDefaultCredentialsSetExplicitly = true;
            }
        }
        
        /// <remarks />
        public event HelloWorldCompletedEventHandler HelloWorldCompleted;
        
        /// <remarks />
        [System.Web.Services.Protocols.SoapDocumentMethodAttribute("http://127.0.0.1:8012/Androidhelloo.asmx", RequestNamespace = "http://127.0.0.1:8012/Androidhelloo.asmx", ResponseNamespace = "http://127.0.0.1:8012/Androidhelloo.asmx", Use = System.Web.Services.Description.SoapBindingUse.Literal, ParameterStyle = System.Web.Services.Protocols.SoapParameterStyle.Wrapped)]
        public string HelloWorld() {
           <big> object[] results = this.Invoke("HelloWorld", new object[0]);</big>
            return ((string)(results[0])); //Error Come here in reference.cs file
        }
        
        /// <remarks />
        public void HelloWorldAsync() {
            this.HelloWorldAsync(null);
        }
        
        /// <remarks />
        public void HelloWorldAsync(object userState) {
            if ((this.HelloWorldOperationCompleted == null)) {
                this.HelloWorldOperationCompleted = new System.Threading.SendOrPostCallback(this.OnHelloWorldOperationCompleted);
            }
            this.InvokeAsync("HelloWorld", new object[0], this.HelloWorldOperationCompleted, userState);
        }
        
        private void OnHelloWorldOperationCompleted(object arg) {
            if ((this.HelloWorldCompleted != null)) {
                System.Web.Services.Protocols.InvokeCompletedEventArgs invokeArgs = ((System.Web.Services.Protocols.InvokeCompletedEventArgs)(arg));
                this.HelloWorldCompleted(this, new HelloWorldCompletedEventArgs(invokeArgs.Results, invokeArgs.Error, invokeArgs.Cancelled, invokeArgs.UserState));
            }
        }
        
        /// <remarks />
        public new void CancelAsync(object userState) {
            base.CancelAsync(userState);
        }
        
        private bool IsLocalFileSystemWebService(string url) {
            if (((url == null) 
                        || (url == string.Empty))) {
                return false;
            }
            System.Uri wsUri = new System.Uri(url);
            if (((wsUri.Port >= 1024) 
                        && (string.Compare(wsUri.Host, "localHost", System.StringComparison.OrdinalIgnoreCase) == 0))) {
                return true;
            }
            return false;
        }
    }
    
    /// <remarks />
    [System.CodeDom.Compiler.GeneratedCodeAttribute("System.Web.Services", "4.0.30319.17929")]
    public delegate void HelloWorldCompletedEventHandler(object sender, HelloWorldCompletedEventArgs e);
    
    /// <remarks />
    [System.CodeDom.Compiler.GeneratedCodeAttribute("System.Web.Services", "4.0.30319.17929")]
    [System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.ComponentModel.DesignerCategoryAttribute("code")]
    public partial class HelloWorldCompletedEventArgs : System.ComponentModel.AsyncCompletedEventArgs {
        
        private object[] results;
        
        internal HelloWorldCompletedEventArgs(object[] results, System.Exception exception, bool cancelled, object userState) : 
                base(exception, cancelled, userState) {
            this.results = results;
        }
        
        /// <remarks />
        public string Result {
            get {
                this.RaiseExceptionIfNecessary();
                return ((string)(this.results[0]));
            }
        }
    }
}

#pragma warning restore 1591