A stateless web application means that the server creates a new instance of the web page every time you request a web page. Every time you submit a request to the server, the information entered by the user in text boxes is sent to the server, but it isn't returned to the browser. Such requests can make you lose the data in each of such trips.
The ASP.NET page framework provides you with different state management features to preserve the control values and properties between such round trips to overcome such limitations.
The state management techniques are of two types:
- Server-Side State Management
- Client-Side State Management
The View State falls under Client Side State Management. Some other techniques in the Client State include Control State, Hidden Fields, and Cookies, and some of the Server Side State Management are Application State, Session State, etc.
What is View State in ASP.NET?
View State is one of the methods of the ASP.NET page framework used to preserve and store the page and control values between round trips. It is maintained internally as a hidden field in the form of an encrypted value and a key.
Default enables the View State for a page. When the browser renders the HTML markup, the current state and the page values are retained and serialized into base64-encoded strings.
The View State methods differ from the cache and cookies because the cookies are accessible from all the pages on your website, while the View State values are non-transferable, and thus you cannot access from different pages.
What are the Features of the View State in ASP.NET?
The view state persists the ASP.NET page framework's control settings between post-backs and sessions. You can use the view state to do the following:
- Retain the control value on a page without storing them in a user profile or session state.
- Store page values and control properties that you set or define on a page.
- Create a custom View State Provider to store the view page information in a SQL Server Database or another database.
What are the Data Objects that can be stored in the View State?
View State can handle several data objects. A few of them are:
- String
- Boolean Value
- Array Object
- Array List Object
- Hash Table
- Custom type Converters
It's possible to store other data types too. The only condition is that you must compile the class with the Serializable attribute to serialize the values for View State.
What are the Advantages of View State?
Some of the primary advantages of the View State in ASP.NET are:
Simplicity and Ease of Use
There is no need for complex codes and logical thinking to implement ViewState. It is simple and makes storing form data between page submissions easy.
Flexibility
It is easy to enable, configure, and disable View State properties on a control-by-control basis. Hence the developer may also choose to implement it at a page level or a control level.
Server-Independent
There are absolutely no server resources required to use View State. It is contained in a structure within the page load.
Enhanced Security
The View State values go through hashing, encoding, and compression for Unicode implementation.
What are the Disadvantages of View State?
Along with the benefits, the View State also comes with a few prominent drawbacks that may put a developer in a dilemma of "to use it or not to use it" based on their needs. Some of those drawbacks are:
Performance
Storing large amounts of data on the View State affects the performance of your page, i.e., it takes more time to load the page, and your page appears to be slow.
Device Limitations
Storing vast chunks of data on the View State requires sufficiently larger memory, which might cause problems when you view your page on a mobile device because of its memory limitations.
Security Risk
Since the View State values are directly visible to anyone when viewing the page source, it is inadvisable to store sensitive data here. If security is a concern, use a Server-based state mechanism instead.
No Auto-Track
The View State does not track fields and values across pages. Its information does not transfer from one page to another.
When Should You Use View State?
The use cases of View State vary from person to person, depending on individual needs and priorities. However, the most common scenarios of their use are:
Case 1
When you need to store or preserve data or control values between postbacks that are non-default.
Case 2
When you need to store application data that is not specific to a page.
How to Enable and Disable View State?
View State can be enabled and disabled for a single control as well as at the page level. Set the EnableViewState attribute of a single control to false to disable View State for that control.
TextBox1.EnableViewState=false;
To disable the View State for an entire page, set the page directive's EnableViewState to false as seen below:
<%Page Language="C#" EnableViewState="false";
You must use the same property and set it to "True" to enable the same.
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Conclusion
View State provides the state information and control values of a specific ASP.NET page. If you need to access that data across multiple pages or throughout your website, consider using other state management techniques like application state, session state, or profile properties.
Another important consideration while choosing View State might be the size of the data to be stored or preserved. If the amount of data is big, it might slow down your website's performance, making it slow.
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If you have any questions for us, leave them in the comments section of this article and our experts will get back to you right away.
