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HtmlInputText.OnServerChange(EventArgs) Method

  • Reference

Definition

Namespace:
System.Web.UI.HtmlControls
Assembly:
System.Web.dll

Raises the ServerChange event.

protected:
 virtual void OnServerChange(EventArgs ^ e);
protected virtual void OnServerChange (EventArgs e);
abstract member OnServerChange : EventArgs -> unit
override this.OnServerChange : EventArgs -> unit
Protected Overridable Sub OnServerChange (e As EventArgs)

Parameters

e
EventArgs

An EventArgs that contains event data.

Examples

The following code example demonstrates how to specify and code a handler for the ServerChange event. The custom event handler updates a label on the Web page to display the value of the text entered into the <input type=text> HTML element.


<%@ Page Language="C#" AutoEventWireup="True" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
    <title>HtmlInputText ServerChange Example</title>
<script runat="server">

      void Server_Change(object sender, EventArgs e) 
      {
         Span1.InnerHtml = "You typed: " + Text1.Value;
      }

      void Page_Load(object sender, EventArgs e)
      {
         // Create an EventHandler delegate for the method you want to
         // handle the event, and then add it to the list of methods
         // called when the event is raised.
         Text1.ServerChange += new System.EventHandler(this.Server_Change);
      }         

   </script>

</head>

<body>

   <form id="form1" runat="server">

      <h3>HtmlInputText ServerChange Example</h3>

      Enter a value in the input field below and 
      click the Submit button.

      <br />

      <input type="text" 
             id="Text1" 
             runat="server"/>
      <br />

      <br />

      <input type="submit" 
             id="Button1" 
             value="Submit" 
             runat="server"/>

      <br />

      <span id="Span1" 
            runat="server" />

   </form>

</body>
</html>


<%@ Page Language="VB" AutoEventWireup="True" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
    <title>HtmlInputText ServerChange Example</title>
<script runat="server">

     Sub Server_Change(ByVal sender As Object, ByVal e As EventArgs)

       Span1.InnerHtml = String.Format("You typed: {0}", Text1.Value)

     End Sub

     Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)

       ' Create an EventHandler delegate for the method you want to
       ' handle the event, and then add it to the list of methods
       ' called when the event is raised.
       AddHandler Text1.ServerChange, AddressOf Server_Change
      
     End Sub

   </script>

</head>

<body>

   <form id="form1" runat="server">

      <h3>HtmlInputText ServerChange Example</h3>

      Enter a value in the input field below and 
      click the Submit button.

      <br />

      <input type="text" 
             id="Text1" 
             runat="server"/>
      <br />

      <input type="submit" 
             id="Button1" 
             value="Submit" 
             runat="server"/>

      <br />

      <span id="Span1" 
            runat="server" />

   </form>

</body>
</html>

Remarks

The ServerChange event is raised when the Value property is changed on the server.

Note

The control must have view state enabled for the ServerChange event to work correctly.

Raising an event invokes the event handler through a delegate. For more information, see Handling and Raising Events.

The OnServerChange method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

Notes to Inheritors

When overriding OnServerChange(EventArgs) in a derived class, be sure to call the base class's OnServerChange(EventArgs) method so that registered delegates receive the event.

Applies to

See also