Export (0) Print
Expand All
Expand Minimize
This topic has not yet been rated - Rate this topic

Page.RegisterRequiresControlState Method

Registers a control as one whose control state must be persisted.

Namespace:  System.Web.UI
Assembly:  System.Web (in System.Web.dll)
public void RegisterRequiresControlState(
	Control control
)

Parameters

control
Type: System.Web.UI.Control

The control to register.

ExceptionCondition
ArgumentException

The control to register is null.

InvalidOperationException

The RegisterRequiresControlState method can be called only before or during the PreRender event.

Custom server controls that use control state must call the RegisterRequiresControlState method on each request because registration for control state is not carried over from request to request during a postback event. It is recommended that registration occur in the Init event.

The following code example shows a custom server control calling the RegisterRequiresControlState method.

public class Sample : Control {
    private int currentIndex = 0;

    protected override void OnInit(EventArgs e) {
        Page.RegisterRequiresControlState(this);
        base.OnInit(e);
    }

    protected override object SaveControlState() {
        return currentIndex != 0 ? (object)currentIndex : null;
    }

    protected override void LoadControlState(object state) {
        if (state != null) {
            currentIndex = (int)state;
        }
    }
}

.NET Framework

Supported in: 4.5.1, 4.5, 4, 3.5, 3.0, 2.0

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Did you find this helpful?
(1500 characters remaining)
Thank you for your feedback
Show:
© 2014 Microsoft. All rights reserved.