ViewState Management Technique

Question

Hi............ I am doing a work in asp.net and face a problem in statemanagement technique.How can we use state management technique in web page. Define view state for the web page application?

Anuja Pawar · Answer

Viewstate represents the state of the page when it was last processed on the server. We use it to retain values across two successive requests for the same page. It is a hidden field added to the page and is restored on the server before the page request is processed. The Viewstate information travels back and forth with the page itself but contains no visual elements that need to be rendered. So you must be thinking that this is fantastic news for the web developer. But (there is always a but) the extra information in the Viewstate adds to the size of the page and the information that travels down the wire. I have seen web pages that have an additional 20Kbytes of Viewstate information. viewstate isoptional but it is enabled by default. In addition the viewstate is not simply a way of reducing your bandwidth. It is rather functional to the implementation of the Web Forms model. Every .aspx page derives from the Page class or Page control and extends it. The default value for the EnableViewState property for the page is True . Through that property we can get or set(enable-disable) the view state of the control.

Satyapriya Nayak · Answer

Hi Aaron Web pages are recreated each time the page is posted to the server. In traditional Web programming this would ordinarily mean that all information associated with the page and the controls on the page would be lost with each round trip. To overcome this inherent limitation of traditional Web programming the ASP.NET page framework includes various options to help you preserve changes — that is for managing state. The page framework includes a facility called view state that automatically preserves property values of the page and all the controls on it between round trips. However you will probably also have application-specific values that you want to preserve. To do so you can use one of the state management options. Client-Based State Management Options: View State Hidden Form Fields Cookies Query Strings Server-Based State Management Options Application State Session State Database Support View State: View State can be used to store state information for a single user. View State is a built in feature in web controls to persist data between page post backs. You can set View State on/off for each control using EnableViewState property. By default EnableViewState property will be set to true. View state mechanism poses performance overhead. View state information of all the controls on the page will be submitted to server on each post back. To reduce performance penalty disable View State for all the controls for which you don't need state. (Data grid usually doesn't need to maintain state). You can also disable View State for the entire page by adding EnableViewState=false to @page directive. View state data is encoded as binary Base64 - encoded which add approximately 30% overhead. Care must be taken to ensure view state for a page is smaller in size. View State can be used using following syntax in an ASP.NET web page. Refer http://www.codeproject.com/KB/vista/ASPNet_State_Management.aspx Thanks