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HtmlTextArea.OnPreRender Method

Raises the PreRender event.

Namespace:  System.Web.UI.HtmlControls
Assembly:  System.Web (in System.Web.dll)

protected internal override void OnPreRender(
	EventArgs e
)

Parameters

e
Type: System.EventArgs

An EventArgs object that contains the event data.

The OnPreRender method notifies the HtmlTextArea control to perform any necessary steps prior to saving the view state and rendering content.

The OnPreRender method is used primarily by control developers extending the functionality of the HtmlTextArea control.

Notes to Inheritors

When overriding the OnPreRender method in a derived class, be sure to call the base class's OnPreRender method so that the HtmlTextArea control is properly registered with the page.

The following code example demonstrates how to override the OnPreRender method to always display 5 rows and 75 columns in a custom HtmlTextArea server control.

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" Assembly="Samples.AspNet.CS" %>
<%@ 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">
<script runat="server">
  void Page_Load(Object sender, EventArgs e)
  {

    HtmlTextArea1.Value = "Hello Html Text Area World.";

  }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head>
    <title>Custom HtmlTextArea OnPreRender Example</title>
  </head>

  <body>
    <form id="Form1" 
          method="post" 
          runat="server">

      <h3>Custom HtmlTextArea OnPreRender Example</h3>

      <aspSample:CustomHtmlTextAreaOnPreRender 
        id="HtmlTextArea1" 
        name="HtmlTextArea1" 
        runat="server" 
        rows="4" 
        cols="50" />

    </form>
  </body>
</html>
using System.Web;
using System.Security.Permissions;

namespace Samples.AspNet.CS.Controls
{
    [AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)]
    public sealed class CustomHtmlTextAreaOnPreRender : System.Web.UI.HtmlControls.HtmlTextArea
    {
        protected override void OnPreRender(System.EventArgs e)
        {
            // Call the base class's OnPreRender method. 
            base.OnPreRender(e);

            // Always display this control with 5 rows and 75 columns. 
            this.Rows = 5;
            this.Cols = 75;
        }
    }
}

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

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.

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