ViewState is an important aspect of web forms development. It is a hidden state on the server-side that keeps the data of web controls, such as text boxes, check boxes and radio buttons. ViewState helps the web application stateful, and permits consistent navigation of pages without losing data. However, it also has a downside to performance because every time, the web page is posted back, it transfers the ViewState from the server to the client and then back to the server, which increases the size of the HTTP requests issued to the server. Over time, this can cause slow performance of the application.

Fortunately, there are effective ways to enable ViewState, which enhances web form performance. This article highlights some of the best ways to accomplish improved Viewstate performance.

1. Keep ViewState as small as possible

The smaller the ViewState, the faster the web form performance. It is essential to design web pages that create minimal ViewState. One way to reduce the ViewState size is to disable ViewState for controls that do not need to maintain their state. In addition, minimisation of the size of the rendered HTML document can also help in reducing the size of the ViewState.

2. Use Compression for ViewState

Compressing the ViewState can help to reduce the size of the view state transmitted back and forth between the client and the server. This can be done by including the “PageCompressionFilter” module in the web application, which helps to compress the ViewState information. To enable this filter, you can add the following code to the web.config file:

```

```

3. Use ViewState Encryption

ViewState encryption provides additional security to protect the ViewState data from being tampered with. Using the ViewStateEncryptionMode setting in the web.config file, you can enable ViewState encryption as shown below:

```

assembly="System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"/>

assembly="System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"/>

Always

```

4. Use Server-Side ViewState

Server-side ViewState stores the ViewState on the server instead of transferring to and from the client between page loads. This reduces the amount of data transmitted between the client and server, improving overall performance. To enable server-side ViewState, you must assign a unique ID to each page so that the ViewState data can be saved and retrieved between postbacks.

```

protected override PageStatePersister PageStatePersister

{

// Create a new StateBagPersister to use to persist the ViewState.

// The StateBagPersister only stores values that were modified, which can lead to more

// efficient use of server storage.

get { return new SessionPageStatePersister(this); }

}

```

5. Disable Controls that Don't Require ViewState

Enabling ViewState for all the controls in a web form is a mistake. Therefore, you need to disable ViewState for controls that don't require it. A good example of a control that doesn't require ViewState is the “Label” control. Viewstate can be turned off for all controls by adding the attribute “EnableViewState” to the web form, and setting it to false.

```

<%@ Page Language="C#" EnableEventValidation="true" AutoEventWireup="true"

CodeBehind="MyPage.aspx.cs" Inherits="MyApplication.MyPage"

EnableViewState="false" %>

```

In conclusion, ViewState is an essential part of web form development, but it could potentially degrade the performance of the web application. By implementing the methods outlined above, developers can significantly improve the performance of their web forms. Therefore, it is important to be aware of these performance tips when designing web forms.