Hi,
Now we will modify the application that we developed in the previous post to work with parameters
http://nishantrana.wordpress.com/2007/10/18/calling-aspnet-webservice-from-javascript-ajax/
1) First we will modify the default Hello World service to accept a parameter like this
[WebMethod]
public string HelloWorld(string Name)
{
return “Hello “+Name+”!”;
}
2) Add the html textbox control in the webform
<INPUT type=”text” id=”Info”>
3) Add the following in the body
<BODY onload=”getMessage()”>
4) Put the following script in our webpage.
<script language=”javascript”>
var xmlHttp;
function getMessage()
{
xmlHttp=new ActiveXObject(”Microsoft.XMLHTTP”);
xmlHttp.open(”get”, “http://localhost/WebService1/Service1.asmx/HelloWorld? name=’Nishant’”, true);
xmlHttp.onreadystatechange=doUpdate;
xmlHttp.send(); return false;
}
function doUpdate()
{
if(xmlHttp.readyState==4)
{
var xmlDoc=xmlHttp.responseXML;
var responseElement=xmlDoc.getElementsByTagName(”string”)[0];
var respText=responseElement.firstChild.nodeValue;
document.forms[0].elements['Info'].value=respText;
}
}
</script>
5) We have changed the method of passing the data to server from post to get as we are passing the value for Name by appending it in the url.
6) Right now if we run the application it will give us error as “object not found”.
7) The reason for the error is that we have to make our web service configured for get method.
8- We need to open web.config of our web service and add the following line inside system.web section
<webServices>
<protocols>
<add name=”HttpGet”/>
</protocols>
</webServices>
9) We need to build the service again
10) This time our application should work without any error.
Bye
Posted in ASP.NET, Ajax | Tags: ASP.NET AJAX
