How to call code behind method from a javascript function?

Question

I am having an javascript function for a HTML img click event in aspx page. And a server Method in its code behind page.Now I want to call the server method from the javascript function without any parameter only when the HTML img is clicked by the user.

C# Code Behind Method:

[WebMethod]
public void PopUpClick(object sender, EventArgs e)
{
    //Something;
}

JavaScriptMethod:

 $(document).ready(function () {

    $('.clickme').click(function () {
        PageMethods.PopUpClick();
    });

});

Also I added into the master page: <asp:ScriptManager ID="ScriptManager1" runat="server" EnablePartialRendering="true" EnablePageMethods="true" />

It is not working.When I debugging this Javascript function on the Chrome I saw an error:Uncaught Reference Error:PageMethods is not defined.

Solution 1

.aspx

     <div>
        <p>Say bye-bey to Postbacks.</p>

        <asp:ScriptManager ID="ScriptManager1" runat="server" EnablePageMethods="true"></asp:ScriptManager>
        <asp:TextBox ID="txtname" runat="server"></asp:TextBox>
        <br />
        <asp:TextBox ID="txtaddress" runat="server"></asp:TextBox>
        <br />
        <asp:Button ID="btnCreateAccount" runat="server" Text="Signup" OnClientClick="HandleIT(); return false;" />
    </div>

JavaScript

<script type="text/javascript">
        function HandleIT() {
            var name = document.getElementById('<%=txtname.ClientID %>').value;
            var address = document.getElementById('<%=txtaddress.ClientID %>').value;
            PageMethods.ProcessIT(name, address, onSucess, onError); 
            function onSucess(result) {
                alert(result);
            }
            function onError(result) {
                alert('Something wrong.');
            }
        }
    </script>

C#

 [WebMethod]
    public static string ProcessIT(string name, string address)
    {
        string result = "Welcome Mr. " + name + ". Your address is '" + address + "'.";
        return result;
    }

Solution 2

The WebMethods that are defined must be "static".

The following ajax call to a WebMethod "GetAllRegions" works fine, provided, the WebMethod is defined as static!!

$.ajax({
  type: "POST",
  url: 'GenerateEAInHtml.aspx/GetAllRegions',
  data: "{}",
  contentType: "application/json; charset=utf-8",
  dataType: "json",
});

The WebMethod is defined this way:

[WebMethod]
public static List<Region> GetAllRegions()
{
  /* Your Code goes here */
  return regions;
}

You might want to use this Ajax Post to also pass JSON data to the WebMethod by passing the data parameter!! This should help.

Solution 3

Assumption that your page name is abc.aspx and xyz is the function name that you have to call. javascript :

function sendData(offset) {
    $.ajax({
    type: "POST",
    url: "abc.aspx/xyz",
    contentType: "application/json; charset=utf-8",
    dataType: "json"
    });
}

Server Side : add Imports System.Web.Script.Serialization

WebMethod(enableSession:=True) _
Public Shared Function xyz() As String
    your code here
End Function

Add module in web.config -> system.webServer

->system.webServer>
    ->modules>
    ->add name="ScriptModule" preCondition="managedHandler" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
    ->/modules>
->/system.webServer>

Solution 4

Back end C# code is separate from your front end JavaScript code. JS runs on the client side and C# runs server side. In order to have front end code fire off a back end functions, you would either need your function to do a form postback or use Ajax (or an equivalent) to call that pages function.

View more solutions

Comments

[musefan]

Try what? You have just posted part of the OP's code, which they already have

[Tapas Mahata]

No, it's not the same. Keep a close look. ;)

[musefan]

OK, so you have made it static, how is that going to help?

[user2729114]

because I have to creating of this image in code behind into a method like this. return "<span style='color:red;font-size:12px;font-weight:bold;'>....</spa‌​n><img style='width:112px; heigh:37px' src='...' class='clickme' />";

[Tapas Mahata]

That could be a probable solution for the error "Uncaught Reference Error:PageMethods is not defined."

[user2729114]

I can't using static because the page and some variable in the methods are not static.

[musefan]

This won't fix that problem. The error shown is a javascript error, you wont fix that by making a code behind method static

[Tapas Mahata]

@user2729114 : Some common useful tips 1.The page method must have the System.Web.Services.WebMethod attribute. [WebMethod] 2.The page method must be public. [WebMethod] public ... 3.The page method must be static. [WebMethod] public static ... 4.The page method must be defined on the page (either inline or in the code-behind). It cannot be defined in a control, master page, or base page. 5.The ASP.NET AJAX Script Manager must have EnablePageMethods set to true.

[musefan]

@TapasMahata: If all that is true, then why don't you make that part of your answer. Then I will remove my downvote

[Tapas Mahata]

@musefan: please have a look on this similar post stackoverflow.com/questions/8188291/pagemethods-not-defined

[musefan]

@TapasMahata: Why? How does that make your answer any better?

[Rich Hopkins]

Thanks so much! Very helpful, even two years later, almost to the day!