EnableViewState

EnableViewState is a property in ASP.NET that controls whether view state is enabled for a web page or a specific control. View state is a mechanism used by ASP.NET to persist control values across postbacks. When enabled, the server sends hidden input fields to the client browser containing the state of the controls. Upon a postback, the browser sends these hidden fields back to the server, allowing ASP.NET to restore the control states without needing to query the data source again.

Setting EnableViewState to true, which is the default behavior for most ASP.NET controls, allows for automatic state management. This simplifies development as developers do not need to manually manage control data between requests. However, enabling view state can increase the size of the HTML output sent to the client, potentially impacting performance, especially on pages with many controls or large amounts of data. It also introduces a security consideration, as view state data can be inspected by the client.

Conversely, setting EnableViewState to false disables this feature for the page or control. When view state is disabled, the server does not generate hidden fields for view state, reducing the page size and potentially improving performance. However, developers must then manually manage control data, often by using session state, cookies, or re-querying the data source on each postback. This is a common optimization technique for performance-critical applications or pages where sensitive data is displayed. The choice between enabling and disabling view state depends on the specific requirements of the application regarding state management, performance, and security.