EmptyControlCollection Class
Definition
Provides standard support for a ControlCollection collection that is always empty.
public ref class EmptyControlCollection : System::Web::UI::ControlCollection
public class EmptyControlCollection : System.Web.UI.ControlCollection
type EmptyControlCollection = class
inherit ControlCollection
Public Class EmptyControlCollection
Inherits ControlCollection
- Inheritance
Examples
/* File name: emptyControlCollection.cs. */
using System;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Collections;
namespace CustomControls
{
// Defines a simple custom control.
public class MyCS_EmptyControl : Control
{
[System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name="FullTrust")]
protected override ControlCollection CreateControlCollection()
/*
* Function Name: CreateControlCollection.
* Denies the creation of any child control by creating an empty collection.
* Generates an exception if an attempt to create a child control is made.
*/
{
return new EmptyControlCollection(this);
}
[System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name="FullTrust")]
protected override void CreateChildControls()
/*
* Function Name: CreateChildControls.
* Populates the child control collection (Controls).
* Note: This function will cause an exception because the control does not allow
* child controls.
*/
{
// Create a literal control to contain the header and add it to the collection.
LiteralControl text;
text = new LiteralControl("<h5>Composite Controls</h5>");
Controls.Add(text);
}
}
}
' File name: emptyControlCollection.vb.
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Collections
Namespace CustomControls
Public Class MyVB_EmptyControl
Inherits Control
<System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
Protected Overrides Function CreateControlCollection() As ControlCollection
' Function Name: CreateControlCollection.
' Denies the creation of any child control by creating an empty collection.
' Generates an exception if an attempt to create a child control is made.
Return New EmptyControlCollection(Me)
End Function
<System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
Protected Overrides Sub CreateChildControls()
' Sub Name: CreateChildControls.
' Populates the child control collection (Controls).
' Note: This function will cause an exception because the control does not allow
' child controls.
Dim text As LiteralControl
text = New LiteralControl("<h5>Composite Controls</h5>")
Controls.Add(text)
End Sub
End Class
End Namespace
Remarks
This class is used when you want to define a custom control that does not allow child controls.
Constructors
EmptyControlCollection(Control) |
Initializes a new instance of the EmptyControlCollection class. |
Properties
Count |
Gets the number of server controls in the ControlCollection object for the specified ASP.NET server control. (Inherited from ControlCollection) |
IsReadOnly |
Gets a value indicating whether the ControlCollection object is read-only. (Inherited from ControlCollection) |
IsSynchronized |
Gets a value indicating whether the ControlCollection object is synchronized. (Inherited from ControlCollection) |
Item[Int32] |
Gets a reference to the server control at the specified index location in the ControlCollection object. (Inherited from ControlCollection) |
Owner |
Gets the ASP.NET server control to which the ControlCollection object belongs. (Inherited from ControlCollection) |
SyncRoot |
Gets an object that can be used to synchronize access to the collection of controls. (Inherited from ControlCollection) |
Methods
Add(Control) |
Denies the addition of the specified Control object to the collection. |
AddAt(Int32, Control) |
Denies the addition of the specified Control object to the collection, at the specified index position. |
Clear() |
Removes all controls from the current server control's ControlCollection object. (Inherited from ControlCollection) |
Contains(Control) |
Determines whether the specified server control is in the parent server control's ControlCollection object. (Inherited from ControlCollection) |
CopyTo(Array, Int32) |
Copies the child controls stored in the ControlCollection object to an Array object, beginning at the specified index location in the Array. (Inherited from ControlCollection) |
Equals(Object) |
Determines whether the specified object is equal to the current object. (Inherited from Object) |
GetEnumerator() |
Retrieves an enumerator that can iterate through the ControlCollection object. (Inherited from ControlCollection) |
GetHashCode() |
Serves as the default hash function. (Inherited from Object) |
GetType() |
Gets the Type of the current instance. (Inherited from Object) |
IndexOf(Control) |
Retrieves the index of a specified Control object in the collection. (Inherited from ControlCollection) |
MemberwiseClone() |
Creates a shallow copy of the current Object. (Inherited from Object) |
Remove(Control) |
Removes the specified server control from the parent server control's ControlCollection object. (Inherited from ControlCollection) |
RemoveAt(Int32) |
Removes a child control, at the specified index location, from the ControlCollection object. (Inherited from ControlCollection) |
ToString() |
Returns a string that represents the current object. (Inherited from Object) |
Extension Methods
Cast<TResult>(IEnumerable) |
Casts the elements of an IEnumerable to the specified type. |
OfType<TResult>(IEnumerable) |
Filters the elements of an IEnumerable based on a specified type. |
AsParallel(IEnumerable) |
Enables parallelization of a query. |
AsQueryable(IEnumerable) |
Converts an IEnumerable to an IQueryable. |