Can you explain the process of storing and retrieving control state data in ASP.NET?
The process of storing and retrieving control state data in ASP.NET involves implementing the necessary methods and using the provided infrastructure. Here's a step-by-step explanation:
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Enable Control State:
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Set the EnableViewState property of the control to true. This enables both view state and control state for the control.
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Save Control State:
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Override the SaveControlState method of the control class. This method is responsible for saving the control state data.
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In the SaveControlState method, store the control-specific data that you want to persist as control state. This data should be serializable.
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Call the base implementation of SaveControlState to include the control state of the base control class.
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Return the serialized control state data as an object from the SaveControlState method.
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Load Control State:
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Override the LoadControlState method of the control class. This method is responsible for loading the control state data.
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In the LoadControlState method, retrieve the saved control state data and assign it to the appropriate control properties or fields.
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Perform any necessary deserialization or type casting.
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Call the base implementation of LoadControlState to load the control state of the base control class.
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Persistence and Retrieval:
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ASP.NET takes care of automatically persisting and retrieving the control state data during the page life cycle.
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The control state is stored as a part of the page's hidden form field and is sent back to the server during postbacks.
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ASP.NET internally calls the SaveControlState and LoadControlState methods to serialize and deserialize the control state data.
With these steps in place, the control state data will be automatically stored and retrieved during the page life cycle. The control-specific data will be maintained and available across postbacks, even if view state is disabled or if controls are dynamically created or removed.
It's important to note that control state has a smaller storage capacity compared to view state, so it should be used for critical control-specific data that is necessary for the control's functionality.