HtmlSelect.RenderChildren Method

Renders the HtmlSelect control's child controls to the specified HtmlTextWriter object.

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

protected public:
virtual void RenderChildren (
	HtmlTextWriter^ writer
) override
protected void RenderChildren (
	HtmlTextWriter writer
)
protected internal override function RenderChildren (
	writer : HtmlTextWriter
)
Not applicable.

Parameters

writer

The HtmlTextWriter that receives the rendered content.

Exception typeCondition

HttpException

Multiple items were selected but the Multiple property is set to false.

The RenderChildren method overrides the base class's RenderChildren method without calling the base method. Each of the <option> elements between the opening and closing <select> tags is rendered with a value attribute, a selected attribute if the item is selected, and its associated text.

If multiple items were selected but the Multiple property is set to false, then an HttpException exception is thrown.

The following code example demonstrates how to override the RenderChildren method so that it always displays default option text in a custom HtmlSelect server control.

No code example is currently available or this language may not be supported.
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.JSL.Controls" Assembly="Samples.AspNet.JSL" %>
<%@ Page Language="VJ#" 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 - RenderChildren - VJ# Example</title>
        <script runat="server">
    void HtmlInputButton1_ServerClick(Object sender, EventArgs e) 
    {
        if (HtmlSelect1.get_SelectedIndex() >= 0) {
            if (HtmlSelect1.get_Multiple() == true) {
                Div1.set_InnerHtml("You selected:");
                for (int i=0; i<=HtmlSelect1.get_Items().get_Count() - 1; i++) {
                    if (HtmlSelect1.get_Items().get_Item(i).
                        get_Selected() == true) {
                        Div1.set_InnerHtml(Div1.get_InnerHtml() + "<br /> &nbsp;&nbsp; " + HtmlSelect1.get_Items().get_Item(i).get_Value()); 
                    }     
                }
            }
            else {
                Div1.set_InnerHtml("You selected " + HtmlSelect1.get_Value());
            }
        }
        else {
            Div1.set_InnerHtml("You did not select an item.");
        }
    } //HtmlInputButton1_ServerClick
        </script>
    </head>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom HtmlSelect - RenderChildren - VJ# Example</h3>
            
            <p>
      <aspSample:CustomHtmlSelectRenderChildren 
        id="HtmlSelect1"  multiple
        name="HtmlSelect1"
        runat="server">
        <option value="Option1">Option1</option>
        <option value="Option2">Option2</option>
        <option value="Option3">Option3</option>
      </aspSample:CustomHtmlSelectRenderChildren>
      </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>

No code example is currently available or this language may not be supported.
package Samples.AspNet.JSL.Controls;

public class CustomHtmlSelectRenderChildren
    extends System.Web.UI.HtmlControls.HtmlSelect
{
    protected void RenderChildren(System.Web.UI.HtmlTextWriter writer)
    {
        // Create a default OPTION.
        System.Web.UI.WebControls.ListItem listItem = 
            new System.Web.UI.WebControls.ListItem("<Select an option> ", "");
        this.get_Items().Insert(0, listItem);
        // Call base's RenderChildren method.
        super.RenderChildren(writer);
    } //RenderChildren
} //CustomHtmlSelectRenderChildren

Windows 98, Windows Server 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

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