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HtmlTextArea.RenderAttributes(HtmlTextWriter) Método

  • Referência

Definição

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

Renderiza os atributos do controle HtmlTextArea no objeto HtmlTextWriter especificado.

protected:
 override void RenderAttributes(System::Web::UI::HtmlTextWriter ^ writer);
protected override void RenderAttributes (System.Web.UI.HtmlTextWriter writer);
override this.RenderAttributes : System.Web.UI.HtmlTextWriter -> unit
Protected Overrides Sub RenderAttributes (writer As HtmlTextWriter)

Parâmetros

writer
HtmlTextWriter

O HtmlTextWriter que recebe o conteúdo renderizado.

Exemplos

O exemplo de código a seguir demonstra como substituir o RenderAttributes método em um controle de servidor personalizado para que o texto de título específico seja sempre exibido para o HtmlTextArea controle.

<%@ 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 RenderAttributes Example</title>
  </head>

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

      <h3>Custom HtmlTextArea - RenderAttributes - C# Example</h3>

      <aspSample:CustomHtmlTextAreaRenderAttributes 
        id="HtmlTextArea1" 
        name="HtmlTextArea1" 
        runat="server" 
        rows="4" 
        cols="50" />
        
    </form>
  </body>
</html>

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Controls" Assembly="Samples.AspNet.VB" %>
<%@ 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">
<script runat="server">

  Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
    
    HtmlTextArea1.Value = "Hello HTML Text Area World."
    
  End Sub
  
</script>

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

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

      <h3>Custom HtmlTextArea RenderAttributes Example</h3>

      <aspSample:CustomHtmlTextAreaRenderAttributes 
        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 CustomHtmlTextAreaRenderAttributes : System.Web.UI.HtmlControls.HtmlTextArea
    {
        protected override void RenderAttributes(System.Web.UI.HtmlTextWriter writer)
        {
            // Write out the Title attribute.
            writer.Write(" Title=\"Text from RenderAttributes.\"");
            
            // Call the base class's RenderAttributes method.
            base.RenderAttributes(writer);
        }
    }
}

Imports System.Web
Imports System.Security.Permissions

Namespace Samples.AspNet.VB.Controls
    <AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
    Public NotInheritable Class CustomHtmlTextAreaRenderAttributes
        Inherits System.Web.UI.HtmlControls.HtmlTextArea

        Protected Overrides Sub RenderAttributes(ByVal writer As System.Web.UI.HtmlTextWriter)

            ' Write out the Title attribute.
            writer.Write(" Title=""Text from RenderAttributes.""")

            ' Call the base class's RenderAttributes method.
            MyBase.RenderAttributes(writer)
        End Sub
    End Class
End Namespace

Comentários

O RenderAttributes método renderiza o name atributo do HtmlTextArea controle diretamente para garantir que ele tenha o mesmo valor que a Control.UniqueID propriedade. Depois de renderizar o atributo, o RenderAttributes método chama o método da RenderAttributes classe base.

O RenderAttributes método é usado principalmente por desenvolvedores de controle que estendem a funcionalidade do HtmlTextArea controle.

Aplica-se a

Confira também