How to Get return value or any value from server side (Code behind) to client side(Javascript) by using AJAX page method concept:

We can Get Return value or any value from to server side (Code behind) to client side(Javascript) by using AJAX page method concept:

Place script manager in a webpage  and

Here we need to enable "EnablePageMethods" Property of ScripManager.

 <asp:ScriptManager ID="ScriptManager1" runat="server" EnablePageMethods="true" >

    </asp:ScriptManager>

Then we need to attach event to the particular return value function

Default.aspx:

==========

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="SearchUser.aspx.cs" Inherits="Wizard.SearchUser" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >

<head runat="server">

    <title></title>

<script type="text/javascript" language="javascript">

   function ValidateEmailAddress_Result(ResultString) 

       {

           var emailAddressErrMsg = document.getElementById("emailAddressErrMsg");

           var btnNextAdd = document.getElementById('<%=btnNext.ClientID %>'); 

           var emailAddressExist = ResultString;

           if (emailAddressExist == 1) 

           {

               emailAddressErrMsg.innerHTML = "Entered email address Already exist.";

               emailAddressErrMsg.style.display = 'inline';

               btnNextAdd.disabled = true;

              

           }

           else 

           {

               emailAddressErrMsg.style.display = 'none';

               btnNextAdd.disabled = false;

           }

       }

        function CheckEmailAddress(src) 

        {

            PageMethods.ValidateEmailAddress(src.value, ValidateEmailAddress_Result);

        }

</script>

</head>

<body>

    <form id="form1" runat="server">

 <asp:ScriptManager ID="ScriptManager1" runat="server" EnablePageMethods="true" >

    </asp:ScriptManager>

    <div>

     

 <asp:TextBox runat="server" ID="txtEmailAddress" Width="250px" 

 AutoCompleteType="Email"  onBlur="CheckEmailAddress(this);"></asp:TextBox>

 <div class="errMessage" id="emailAddressErrMsg" style="display:none;">

                                    *Please enter a Email Address.

                                    </div>

<asp:Button ID="btnNext" runat="server" Text="Submit"  />

    </div>

    </form>

</body>

</html>

Default.aspx.cs:

===========

[System.Web.Services.WebMethod]

        public static int ValidateEmailAddress(string emailAddress)

        {

            try

            {

                int emailAddresscount = CheckEmailAddressExist(emailAddress);

                if (emailAddresscount > 0)

                {

                    return 1;

                }

                else

                {

                    return 0;

                }

            }

            catch { return 0; }

        }

How to send control value or any value from client side(Javascript) to server side (Code behind) by using AJAX page method concept:

We can send control value or any value from client side(Javascript) to server side (Code behind) by using AJAX page method concept:

Place script manager in a webpage  and

Here we need to enable "EnablePageMethods" Property of ScripManager.

 <asp:ScriptManager ID="ScriptManager1" runat="server" EnablePageMethods="true" >

    </asp:ScriptManager>

Default.aspx:

==========

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="SearchUser.aspx.cs" Inherits="Wizard.SearchUser" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >

<head runat="server">

    <title></title>

<script type="text/javascript" language="javascript">

 function startSearch(val) {

    

            PageMethods.SendValueToServerSide(val);

        }

</script>

</head>

<body>

    <form id="form1" runat="server">

 <asp:ScriptManager ID="ScriptManager1" runat="server" EnablePageMethods="true" >

    </asp:ScriptManager>

    <div>

     

        <asp:TextBox ID="txtval" runat="server"></asp:TextBox>

<asp:Button ID="btnSearchInput" runat="server" Text="SendSearchInput" OnClientClick="

startSearch('

txtval.value'

)

" />

    </div>

    </form>

</body>

</html>

Default.aspx.cs:

===========

[System.Web.Services.WebMethod]

  public static void SendValueToServerSide(string  clientsidevalue)

  {      

        string searchinputfromclientside = clientsidevalue;

  }