Export (0) Print
Expand All

HtmlSelect.RenderAttributes Method

Renders the HtmlSelect control's attributes to the specified HtmlTextWriter object.

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

'Declaration
Protected Overrides Sub RenderAttributes ( _
	writer As HtmlTextWriter _
)

Parameters

writer
Type: System.Web.UI.HtmlTextWriter

The HtmlTextWriter that receives the rendered content.

The RenderAttributes method renders the name attribute of the HtmlSelect control directly to ensure that it has the same value as the Control.UniqueID property. After rendering the attribute, the RenderAttributes method calls the base class's RenderAttributes method.

The RenderAttributes method is used primarily by control developers extending the functionality of the HtmlSelect control.

The following code example demonstrates how to override the RenderAttributes method in a custom server control so that specific title text is always displayed for the HtmlSelect control.

<%@ 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">
<html xmlns="http://www.w3.org/1999/xhtml" >
    <head>
        <title>Custom HtmlSelect - RenderAttributes - VB.NET Example</title>
        <script runat="server">
      Sub HtmlInputButton1_ServerClick(sender As Object, e As EventArgs)
        If HtmlSelect1.SelectedIndex >= 0 Then
            If HtmlSelect1.Multiple = True Then
              Div1.InnerHtml = "You selected:"
              Dim i As Integer
              For i = 0 To HtmlSelect1.Items.Count - 1
                  If HtmlSelect1.Items(i).Selected = True Then
                    Div1.InnerHtml += "<br /> &nbsp;&nbsp; " & HtmlSelect1.Items(i).Value
                  End If
              Next i
            Else
              Div1.InnerHtml = "You selected " & HtmlSelect1.Value
            End If
        Else
            Div1.InnerHtml = "You did not select an item."
        End If
      End Sub
        </script>
    </head>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom HtmlSelect - RenderAttributes - VB.NET Example</h3>

            <p>
      <aspSample:CustomHtmlSelectRenderAttributes 
        id="HtmlSelect1" 
        name="HtmlSelect1"
        runat="server">
        <option value="Option1">Option1</option>
        <option value="Option2">Option2</option>
        <option value="Option3">Option3</option>
      </aspSample:CustomHtmlSelectRenderAttributes>
      </p>

      <p>
      <input 
        id="HtmlInputButton1" 
        runat="server" 
        type="button" 
        onserverclick="HtmlInputButton1_ServerClick"
        value="Select" 
        name="HtmlInputButton1" />&nbsp;&nbsp;
      </p>

      <br />
      <div id="Div1" runat="server" 
        style="DISPLAY: inline; WIDTH: 256px; HEIGHT: 15px" />

        </form>
    </body>
</html>
<AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
Public NotInheritable Class CustomHtmlSelectRenderAttributes
    Inherits System.Web.UI.HtmlControls.HtmlSelect

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

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

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

.NET Framework

Supported in: 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.

Show:
© 2014 Microsoft