If statement in aspx page

I want to write a basic if statement on my site to display either item 1 or item 2 depending on if a variable is set to true.

I'm not too familiar with .NET and need a little help with the basic structure of how to get an if statement to work on the aspx page

if the purpose is to show or hide a part of the page then you can do the following things

1. wrap it in markup with

   <% if(somecondition) { %> some html <% } %>

2. Wrap the parts in a Panel control and in codebehind use the if statement to set the Visible property of the Panel.

Just use simple code

<%
if(condition)
{%>

html code

<% } 
else 
{
%>
html code
<% } %>

Normally you'd just stick the code in Page_Load in your .aspx page's code-behind.

if (someVar) {
    Item1.Visible = true;
    Item2.Visible = false;
} else {
    Item1.Visible = false;
    Item2.Visible = true;
}

This assumes you've got Item1 and Item2 laid out on the page already.

A complete answer for optional content in the header of a VB.NET aspx page using a master page:

 <%@ Page Language="vb" AutoEventWireup="false" MasterPageFile="~/Site.Master" CodeBehind="some_vb_page.aspx.vb" Inherits="some_vb_page" %> 
 <asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server">          
     <% If Request.QueryString("id_query_param") = 123 Then 'Add some VB comment here, 
         'which will not be visible in the rendered source code of the aspx page later %>        
         <!-- add some html content depending on -->
         <!-- the condition in the if statement: -->                
         <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.8/jquery.min.js" type="text/javascript" charset="utf-8"></script>
     <% End If %>
</asp:Content>

Where your current page url is something like:

http://mywebpage.com/some_vb_page.aspx?id_query_param=123

To use C# (C# Script was initialized at 2015) on ASPX page you can make use the following syntax.

Start Tag:- <% End tag:- %> Please make sure that all the C# code must reside inside this <%%> .

Syntax Example:-

• `<%@ Import Namespace="System.Web.UI.WebControls" %>`  (For importing Namespace)
  

Reference to some basic namespaces for working with ASPX page.

`<%@ Import Namespace="System.Web.UI.WebControls" %>
<%@ Import Namespace="System.Diagnostics" %>
<%@ Import Namespace="System" %>
<%@ Import Namespace="System.Web" %>
<%@ Import Namespace="System.Web.UI" %>
<%@ Import Namespace="System.IO" %>`

C# Code:-

`<%
if (Session["New"] != null)
{
    Page.Title = ActionController.GetName(Session["New"].ToString());
}
%>`

Features of C# Script:

• No need of compilation. Run time execution is occurred like Java Script.

Before using C# script make sure the following things:-

• You are on WebForm. Not on WebForm with master page.

• If you are in WebForm with master page make sure that you have written your C# script at Master page file.

• C# script can be inserted anywhere in the aspx page but after the page meta declaration like

  <%@ Master Language="C#" AutoEventWireup="true" CodeBehind="Profile.master.cs" Inherits="OOSDDemo.Profile" %>

  <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="WebApplication3.WebForm1" %> (For WebForm)

<div>
	<% 
		if (true)
		{
	%>
	<div>
		Show true content
	</div>
	<%
		}
		else
		{
	%>
	<div>
		Show false content
	</div>
	<%
		}
	%>
</div>

Here's a simple one written in VB for an ASPX page:

                If myVar > 1 Then
                    response.write("Greater than 1")
                else
                    response.write("Not!")
                End If