How do we achieve this? just follows the steps:
Step 1: Create a project with Asp.net empty web application. and add "Default.aspx" page.
Step 2: In Default.aspx page, add following code.
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<script>
function getRandomNumber() {
$.ajax({
url: "Default.aspx/getRandomNumber",
data: '',
type: "POST",
dataType: "json",
contentType: "application/json; charset=utf-8",
success: function (mydata) {
var i = JSON.parse(mydata.d);
$("#lblRandomNumber").text(i);
}
});
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Button ID="btnRandomNumber" runat="server"
OnClientClick="javascript:getRandomNumber(); return false;"
Text="Get Random Number" />
<asp:Label ID="lblRandomNumber" runat="server" ></asp:Label>
</div>
</form>
</body>
</html>
Step 3: Now, In Default.aspx.vb page, add following code.
Imports System.Web.Services
Imports System.Web.Script.Serialization
Imports System.Web.Script.Services
Public Class _Default
Inherits System.Web.UI.Page
<WebMethod> _
<ScriptMethod(ResponseFormat:=ResponseFormat.Json)> _
Public Shared Function getRandomNumber() As String
Dim s As String = New Random().Next(100).ToString()
Dim ser As New JavaScriptSerializer()
Dim jsonString = ser.Serialize(s)
Return jsonString
End Function
End Class
Step 4: Now run it, and click on "get random number" button to get the random number without postback.
