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 t开发者_如何学编程o 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
<div>
<%
if (true)
{
%>
<div>
Show true content
</div>
<%
}
else
{
%>
<div>
Show false content
</div>
<%
}
%>
</div>
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)
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
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