Create/Build wcf autocomplete/autoextender textbox using database linq c# asp.net

Posted by on August 13, 2010 Leave a comment (0) Go to comments

Introduction:
In this article,i am going to explain about how to create auto complete textbox using wcf with sample application.

Main:
A service for the auto-complete extender can have any number of operations, but all have the same prototype. Here’s
a possible contract,

public string[] GetExtendedText(string prefixText, int count)
  {
     GetAutoTextDataContext objautocontext = new GetAutoTextDataContext();
 
     string[] fulltext = (from n in objautocontext.Emps
                          where n.FirstName.StartsWith(prefixText)
                          select n.FirstName).ToArray();
 
     return fulltext;
   }

in this demonstartion we are just going to call WCF service instead of web service,

Create a new web application and named it WcfAutoCompleteExtender,

Add a class under app_data dir and named it AutoExtender.cs,and define the service contract,

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.ServiceModel;
using System.ServiceModel.Activation;
using System.ServiceModel.Web;
 
namespace WcfAutoCompleteExtender
{
    [ServiceContract(Namespace = "NetProgrammingHelp", Name = "AutoCompleteTextBoxService")]
    public interface IAutoCompleteSvc
    {
        [OperationContract]
        string[] GetExtendedText(string prefixText, int count);
    }
    [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
    public class AutoCompleteservice : IAutoCompleteSvc
    {
        public string[] GetExtendedText(string prefixText, int count)
        {
            GetAutoTextDataContext objautocontext = new GetAutoTextDataContext();
 
            string[] fulltext = (from n in objautocontext.Emps
                                 where n.FirstName.StartsWith(prefixText)
                                 select n.FirstName).ToArray();
 
            return fulltext;
        }
 
 
    }
}

define the ajax behaviours in web.config,

<system.serviceModel>
    <behaviors>
      <endpointBehaviors>
        <behavior name="AjaxServiceBehaviour">
          <enableWebScript />
        </behavior>
      </endpointBehaviors>
    </behaviors>
    <serviceHostingEnvironment aspNetCompatibilityEnabled="true" />
    <services>
      <service name="WcfAutoCompleteExtender.AutoCompleteservice">
        <endpoint address=""
                  behaviorConfiguration="AjaxServiceBehaviour"
                  binding="webHttpBinding"
                  contract="WcfAutoCompleteExtender.IAutoCompleteSvc" />
      </service>
    </services>
  </system.serviceModel>

Add a new text file under solution and named it AutoService.svc,and define the endpoint of this service

<%@ ServiceHost
    Service="WcfAutoCompleteExtender.AutoCompleteservice"
    Language="C#"
    Debug="true"
    CodeBehind="~/App_Data/AutoExtender.cs" %>

Next call the service using auto extender,

<form id="form1" runat="server">
    <ajaxToolkit:ToolkitScriptManager ID="ScriptManager1" runat="server">   
    </ajaxToolkit:ToolkitScriptManager>
 
     <asp:TextBox runat="server" ID="myTextBox" Width="300" autocomplete="off" />        
            <ajaxToolkit:AutoCompleteExtender
                runat="server" 
                ID="autoComplete1" 
                enabled="true"
                TargetControlID="myTextBox"
                ServicePath="~/AutoService.svc"
                ServiceMethod="GetExtendedText"
                MinimumPrefixLength="1" 
                CompletionSetCount="20" 
                CompletionInterval="0000"
                EnableCaching="true">
            </ajaxToolkit:AutoCompleteExtender>     
 
 
    </form>