How does control state ensure that a control's state is preserved even if view state is disabled?
Control state ensures that a control's state is preserved even if view state is disabled by providing a separate mechanism for persisting and retrieving control-specific data. Here's how control state achieves this:
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Independent storage and retrieval:
Control state uses a separate storage mechanism to persist control-specific data. It does not rely on the view state's hidden form field to store the data. Instead, control state data is serialized and stored in a separate hidden field within the page.
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Unaffected by view state settings:
Control state is not affected by the 'EnableViewState' property of the page or other controls. Even if view state is disabled at the page level, control state remains enabled and continues to function independently. This allows control state to persist and retrieve control-specific data, regardless of the view state settings.
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Automatic handling during postbacks:
During postbacks, ASP.NET automatically manages the storage and retrieval of control state data. The control state data is included in the page's hidden form field and sent back to the server. ASP.NET internally invokes the appropriate methods (such as 'SaveControlState' and 'LoadControlState') to serialize and deserialize the control state data.
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Encapsulation within the control:
Control state data is encapsulated within the control itself. It is not accessible or modifiable by other controls or the page. This encapsulation ensures that the control's critical data is securely preserved and maintains data integrity.
By utilizing a separate storage mechanism and being independent of view state settings, control state ensures that a control's specific data is reliably persisted and retrieved, even when view state is disabled. This allows the control to maintain its state and functionality, preserving control-specific information such as user-entered values, custom properties, or dynamically created control structures.