DropDownList.CreateControlCollection Method
Definition
Important
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Creates a collection to store child controls.
protected:
override System::Web::UI::ControlCollection ^ CreateControlCollection();
protected override System.Web.UI.ControlCollection CreateControlCollection ();
override this.CreateControlCollection : unit -> System.Web.UI.ControlCollection
Protected Overrides Function CreateControlCollection () As ControlCollection
Returns
Always returns an EmptyControlCollection.
Examples
The following code example demonstrates how to override the CreateControlCollection method in a custom server control so that it always returns a new instance of the EmptyControlCollection class for the DropDownList control. For information about using custom server controls, see Walkthrough: Developing and Using a Custom Web Server Control.
<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" Assembly="Samples.AspNet.CS" %>
<!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 DropDownList - CreateControlCollection - C# Example</title>
<script runat="server">
private void Page_Load(object sender, System.EventArgs e)
{
DropDownList1.Items.Add(new ListItem("Item1", "Item1"));
DropDownList1.Items.Add(new ListItem("Item2", "Item2"));
DropDownList1.Items.Add(new ListItem("Item2", "Item2"));
}
</script>
</head>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom DropDownList - CreateControlCollection - C# Example</h3>
<aspSample:CustomDropDownListCreateControlCollection
id="DropDownList1"
runat="server" />
</form>
</body>
</html>
<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Controls" Assembly="Samples.AspNet.VB" %>
<!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 DropDownList - CreateControlCollection - VB.NET Example</title>
<script runat="server">
Sub Page_Load(sender As Object, e As EventArgs)
DropDownList1.Items.Add(New ListItem("Item1", "Item1"))
DropDownList1.Items.Add(New ListItem("Item2", "Item2"))
DropDownList1.Items.Add(New ListItem("Item2", "Item2"))
End Sub
</script>
</head>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom DropDownList - CreateControlCollection - VB.NET Example</h3>
<aspSample:CustomDropDownListCreateControlCollection id="DropDownList1" runat="server" />
</form>
</body>
</html>
using System.Web;
using System.Security.Permissions;
namespace Samples.AspNet.CS.Controls
{
[AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)]
public sealed class CustomDropDownListCreateControlCollection : System.Web.UI.WebControls.DropDownList
{
protected override System.Web.UI.ControlCollection CreateControlCollection()
{
// Return a new empty ControlCollection
return new System.Web.UI.EmptyControlCollection(this);
}
}
}
Imports System.Web
Imports System.Security.Permissions
Namespace Samples.AspNet.VB.Controls
<AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
Public NotInheritable Class CustomDropDownListCreateControlCollection
Inherits System.Web.UI.WebControls.DropDownList
Protected Overrides Function CreateControlCollection() As System.Web.UI.ControlCollection
' Return a new EmptyControlCollection
Return New System.Web.UI.EmptyControlCollection(Me)
End Function
End Class
End Namespace
Applies to
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