Page.RegisterRequiresRaiseEvent(IPostBackEventHandler) Method


Registers an ASP.NET server control as one requiring an event to be raised when the control is processed on the Page object.

 virtual void RegisterRequiresRaiseEvent(System::Web::UI::IPostBackEventHandler ^ control);
public virtual void RegisterRequiresRaiseEvent (System.Web.UI.IPostBackEventHandler control);
abstract member RegisterRequiresRaiseEvent : System.Web.UI.IPostBackEventHandler -> unit
override this.RegisterRequiresRaiseEvent : System.Web.UI.IPostBackEventHandler -> unit
Public Overridable Sub RegisterRequiresRaiseEvent (control As IPostBackEventHandler)



The control to register.


The following code example uses the RegisterRequiresRaiseEvent method to register a Button Web server control as requiring an event to be raised. After you have registered the first Button control, you can cause the second Button control declared in the code to post the results of the first button's click event to the page.

void DisplayUserName(Object sender, EventArgs ea) 
   Response.Write("Welcome to " + Server.HtmlEncode(userName.Text));
void RaiseEvent(Object sender, EventArgs ea)
   // Raise a post back event for a control.
   this.RaisePostBackEvent(userButton, "");
void Page_Load(Object sender, EventArgs ea)
   // Register a control as one that requires postback handling.
    Sub DisplayUserName(Sender As Object, e As EventArgs) 
       Response.Write("Welcome to " + Server.HtmlEncode(userName.Text))
    End Sub

   Sub MyRaiseEvent(Sender As Object, e As EventArgs)
       'Raises a post back event for a control.
        Me.RaisePostBackEvent(userButton, "")
   End Sub 
    Sub Page_Load(Sender As Object, e As EventArgs)

      'Registers a control as one that requires postback handling
  End Sub


Only one server control can be registered per page request. The RegisterRequiresRaiseEvent must be used when the control does not include its control ID in the form post data. Also, the control that is registered must implement the IPostBackEventHandler interface.

Applies to

See also