ASP.NET The ViewState

## ASP.NET Tutorial

ASP.NET HOME ASP.NET Intro

## WP Tutorial

WebPages Intro WebPages Razor WebPages Layout WebPages Folders WebPages Global WebPages Forms WebPages Objects WebPages Files WebPages Databases WebPages Helpers WebPages WebGrid WebPages Charts WebPages Email WebPages PHP WebPages Publish WebPages Examples

## WP References

WebPages Classes WebPages Security WebPages Database WebPages WebMail WebPages Helpers

## ASP.NET Razor

Razor Intro Razor Syntax Razor C# Variables Razor C# Loops Razor C# Logic Razor VB Variables Razor VB Loops Razor VB Logic

## ASP.NET MVC

MVC Intro MVC Application MVC Folders MVC Layout MVC Controllers MVC Views MVC Database MVC Models MVC Security MVC HTML Helpers MVC Publish MVC Reference

## WF Tutorials

WebForms Intro WebForms Pages WebForms Controls WebForms Events WebForms Forms WebForms ViewState WebForms TextBox WebForms Button WebForms Data Binding WebForms ArrayList WebForms Hashtable WebForms SortedList WebForms XML Files WebForms Repeater WebForms DataList WebForms DbConnection WebForms Master Pages WebForms Navigation WebForms Examples

## WF References

WebForms HTML WebForms Controls WebForms Validation

# ASP.NET Web Forms - Maintaining the ViewState

« Previous
Next Chapter »

You may save a lot of coding by maintaining the ViewState of the objects in your Web Form.

## Maintaining the ViewState

When a form is submitted in classic ASP, all form values are cleared. Suppose you have submitted a form with a lot of information and the server comes back with an error. You will have to go back to the form and correct the information. You click the back button, and what happens.......ALL form values are CLEARED, and you will have to start all over again! The site did not maintain your ViewState.

When a form is submitted in ASP .NET, the form reappears in the browser window together with all form values. How come? This is because ASP .NET maintains your ViewState. The ViewState indicates the status of the page when submitted to the server. The status is defined through a hidden field placed on each page with a <form runat="server"> control. The source could look something like this:

<form name="_ctl0" method="post" action="page.aspx" id="_ctl0">
<input type="hidden" name="__VIEWSTATE"
value="dDwtNTI0ODU5MDE1Ozs+ZBCF2ryjMpeVgUrY2eTj79HNl4Q=" />
.....some code
</form>

Maintaining the ViewState is the default setting for ASP.NET Web Forms. If you want to NOT maintain the ViewState, include the directive <%@ Page EnableViewState="false" %> at the top of an .aspx page or add the attribute EnableViewState="false" to any control.

Look at the following .aspx file. It demonstrates the "old" way to do it. When you click on the submit button, the form value will disappear:

## Example

<html>
<body>
<form action="demo_classicasp.aspx" method="post">
Your name: <input type="text" name="fname" size="20">
<input type="submit" value="Submit">
</form>
<%
dim fname
fname=Request.Form("fname")
If fname<>"" Then
Response.Write("Hello " & fname & "!")
End If
%>
</body>
</html>
Show example »

Here is the new ASP .NET way. When you click on the submit button, the form value will NOT disappear:

## Example

Click view source in the right frame of the example to see that ASP .NET has added a hidden field in the form to maintain the ViewState

<script runat="server">
Sub submit(sender As Object, e As EventArgs)
lbl1.Text="Hello " & txt1.Text & "!"
End Sub
</script>
<html>
<body>
<form runat="server">
Your name: <asp:TextBox id="txt1" runat="server" />
<asp:Button OnClick="submit" Text="Submit" runat="server" />
<p><asp:Label id="lbl1" runat="server" /></p>
</form>
</body>
</html>
Show example »
« Previous
Next Chapter »

## Your suggestion:

Your E-mail (optional):

Page address:

Description:

Close [X]

## Thank You For Helping Us!

Your message has been sent to W3Schools.

Close [X]
Search w3schools.com:

## WEB HOSTING

Best Web Hosting UK Reseller Hosting Wow! $5 SSD Hosting

## WEB BUILDING

Download XML Editor
FREE Website BUILDER FREE Website Creator

## WEB RESOURCES

Web Statistics Web Validation

## SHARE THIS PAGE